file which includes the original illustrations4 ,see #chahg-;h4htm or #chahg-;h4zip3 7https3_/_/www4gutenberg4org_/cache_/epu b_/#chahg_/pg#chahg-;images4html7 or 7https3_/_/www4gutenberg4org_/files_/#ch ahg_/chahg-;h4zip7 ---------------------------------------- ------------------------- ,,transcriber',s ,,notes ,transcription used for this e-text3 ,italic text in the original work is transcribed between underscores1 as in text2 ,bold face text in the original work is transcribed between equal signs1 as in text2 ,bold face underlined text in the original work is transcribed between tildes1 as in text2 ,super- and subscripts in the original work are transcribed as text and text1 respectively2 ,greek characters have been transcribed as alpha1 beta1 etc42 ,the oe-ligature in ,phoenix has been transcribed as oe4 ,some in-line multi-line formulas have been transcribed as single-line formulas1 where necessary with brackets added4 ,some table headings have been replaced by legends ,a1 ,b1 etc2 these are listed directly above the relevant tables4 ,more extensive ,transcriber's ,notes may be found at the end of this text4 ---------------------------------------- ------------------------- ,,aviation ,,engines ,design--,construction--,operation and ,repair by ,,first ,,lieut4 ,,victor ,w4 ,,page1 ,a4 ,s4 ,s4 ,c41 ,u4 ,s4 ,r4 99 99 99 99 99 ,,just ,,published ,,aviation ,,engines4 ,their ,design1 ,construction1 ,operation and ,repair4 ,by ,lieut4 ,,victor ,w4 ,,page1 ,aviation ,section1 ,s4,c4,u4,s4,r4 ,a practical work containing valuable instructions for aviation students1 mechanicians1 squadron engineering officers and all interested in the construction and upkeep of airplane power plants4 #egf octavo pages4 #bej illustrations4 ,price #c4jj4 ,,aviation ,,chart1 or the ,location of ,airplane ,power ,plant ,troubles ,made ,easy4 ,by ,lieut4 ,,victor ,w4 ,,page1 ,a4,s41 ,s4,c4,u4,s4,r4 ,a large chart outlining all parts of a typical airplane power plant1 showing the points where trouble is apt to occur and suggesting remedies for the common defects4 ,intended especially for aviators and aviation mechanics on school and field duty4 ,price #ej cents4 ,,glossary ,,of ,,aviation ,,terms4 ,compiled by ,lieuts4 ,,victor ,w4 ,,page1 ,a4,s41 ,s4,c4,u4,s4,r4 and ,,paul ,,montariol of the ,french ,flying ,corps on duty at ,signal ,corps ,aviation ,school1 ,mineola1 ,l4 ,i4 ,a complete glossary of practically all terms used in aviation1 having lists in both ,french and ,english1 with equivalents in either language4 ,a very valuable book for all who are about to leave for duty overseas4 ,price1 cloth1 #a4jj4 ,,the ,,norman ,w4 ,,henley ,,publishing ,,company #b ,,west #de,,th ,,st41 ,,new ,,york 99 99 99 99 99 ,illustration3 ,part ,sectional ,view of ,hall-,scott ,airplane ,motor1 ,showing ,principal ,parts4 99 99 99 99 99 ,,censored ,this ,book ,entitled ,,aviation ,,engines ,by ,,lieut4 ,,victor ,w4 ,,page has been censored by the ,united ,states ,government1 and pages and parts of pages have been omitted by special instructions from ,washington4 ,the book has been passed by ,,the ,,committee ,,on ,,public ,,information and is as complete as we can furnish it1 and we so advise the purchaser of it4 ,,the ,,norman ,w4 ,,henley ,,publishing ,,company 99 99 99 99 99 ,,aviation ,,engines ,design--,construction--,operation and ,repair ,a ,complete1 ,practical ,treatise ,outlining ,clearly the ,elements of ,internal ,combustion ,engineering with ,special ,reference to the ,design1 ,construction1 ,operation and ,repair of ,airplane ,power ,plants2 ,also the ,auxiliary ,engine ,systems1 ,such as ,lubrication1 ,carburetion1 ,ignition and ,cooling4 ,it ,includes ,complete ,instructions for ,engine ,repairing and ,systematic ,location of ,troubles1 ,tool ,equipment and ,use of ,tools1 ,also ,outlines the ,latest ,mechanical ,processes4 by ,,first ,,lieut4 ,,victor ,w4 ,,page1 ,a4 ,s4 ,s4 ,c41 ,u4 ,s4 ,r4 ,assistant ,engineering ,officer1 ,signal ,corps ,aviation ,school1 ,mineola1 ,l4 ,i4 ,author of ,the ,modern ,gasoline ,automobile1 ,etc4 ,illustration ,contains ,valuable ,instructions for ,all ,aviation ,students1 ,mechanicians1 ,squadron ,engineering ,officers and ,all ,interested in the ,construction and ,upkeep of ,airplane ,power ,plants4 ,new ,york ,the ,norman ,w4 ,henley ,publishing ,company #b ,west #deth ,street #aiag ,copyrighted1 #aiag ,by ,the ,norman ,w4 ,henley ,publishing ,co4 ,printed in ,u4 ,s4 ,a4 ,all ,illustrations in ,this ,book ,have ,been ,specially ,made by the ,publishers1 and ,their ,use1 ,without ,permission1 ,is ,strictly ,prohibited ,composition1 ,electrotyping and ,presswork by the ,publishers ,printing ,co41 ,new ,york ,,preface ,in presenting this treatise on ,aviation ,engines1 the writer realizes that the rapidly developing art makes it difficult to outline all latest forms or describe all current engineering practice4 ,this exposition has been prepared primarily for instruction purposes and is adapted for men in the ,aviation ,section1 ,signal ,corps1 and students who wish to become aviators or aviation mechanicians4 ,every effort has been made to have the engineering information accurate1 but owing to the diversity of authorities consulted and use of data translated from foreign language periodicals1 it is expected that some slight errors will be present4 ,the writer wishes to acknowledge his indebtedness to such firms as the ,curtiss ,aeroplane and ,motor ,co41 ,hall-,scott ,company1 ,thomas-,morse ,aircraft ,corporation and ,general ,vehicle ,company for photographs and helpful descriptive matter4 ,special attention has been paid to instructions on tool equipment1 use of tools1 trouble shooting and engine repairs1 as it is on these points that the average aviation student is weakest4 ,only such theoretical consideration of thermo-dynamics as was deemed absolutely necessary to secure a proper understanding of engine action after consulting several instructors is included1 the writer's efforts having been confined to the preparation of a practical series of instructions that would be of the greatest value to those who need a diversified knowledge of internal-combustion engine operation and repair1 and who must acquire it quickly4 ,the engines described and illustrated are all practical forms that have been fitted to airplanes capable of making flights and may be considered fairly representative of the present state of the art4 ,,victor ,w4 ,,page1 #ast ,lieut4 ,a4 ,s4 ,s4 ,c41 ,u4 ,s4 ,r4 ,,mineola1 ,l4 ,i41 ,october1 #aiag4 ,,contents ,,pages ,,chapter ,i ,brief ,consideration of ,aircraft ,types--,essential ,requirements of ,aerial ,motors--,aviation ,engines ,must ,be ,light--,factors ,influencing ,power ,needed--,why ,explosive ,motors ,are ,best--,historical--,main ,types of ,internal ,combustion ,engines #ag-cf ,,chapter ,,ii ,operating ,principles of ,two- and ,four-,stroke ,engines--,four-cycle ,action--,two-cycle ,action--,comparing ,two- and ,four-cycle ,types-- ,theory of ,gas and ,gasoline ,engine--,early ,gas-,engine ,forms-- ,isothermal ,law--,adiabatic ,law--,temperature ,computations--,heat and ,its ,work--,conversion of ,heat to ,power--,requisites for ,best ,power ,effect #cg-ei ,,chapter ,,iii ,efficiency of ,internal ,combustion ,engines--,various ,measures of ,efficiency--,temperatures and ,pressures--,factors ,governing ,economy --,losses in ,wall ,cooling--,value of ,indicator ,cards--,compression in ,explosive ,motors--,factors ,limiting ,compression--,causes of ,heat ,losses and ,inefficiency--,heat ,losses to ,cooling ,water #fj-gi ,,chapter ,,iv ,engine ,parts and ,functions--,why ,multiple ,cylinder ,engines ,are ,best --,describing ,sequence of ,operations--,simple ,engines--,four and ,six ,cylinder ,vertical ,tandem ,engines--,eight and ,twelve ,cylinder ,v ,engines--,radial ,cylinder ,arrangement--,rotary ,cylinder ,forms #hj-aji ,,chapter ,v ,properties of ,liquid ,fuels--,distillates of ,crude ,petroleum-- ,principles of ,carburetion ,outlined--,air ,needed to ,burn ,gasoline-- ,what a ,carburetor ,should ,do--,liquid ,fuel ,storage and ,supply-- ,vacuum ,fuel ,feed--,early ,vaporizer ,forms--,development of ,float ,feed ,carburetor--,maybach's ,early ,design--,concentric ,float and ,jet ,type --,schebler ,carburetor--,claudel ,carburetor--,stewart ,metering ,pin ,type--,multiple ,nozzle ,vaporizers--,two-,stage ,carburetor--,master ,multiple ,jet ,type--,compound ,nozzle ,zenith ,carburetor--,utility of ,gasoline ,strainers--,intake ,manifold ,design and ,construction-- ,compensating for ,various ,atmospheric ,conditions--,how ,high ,altitude ,affects ,power--,the ,diesel ,system--,notes on ,carburetor ,installation--,notes on ,carburetor ,adjustment #aaj-aed ,,chapter ,,vi ,early ,ignition ,systems--,electrical ,ignition ,best--,fundamentals of ,magnetism ,outlined--,forms of ,magneto--,zones of ,magnetic ,influence --,how ,magnets are ,made--,electricity and ,magnetism ,related--,basic ,principles of ,magneto ,action--,essential ,parts of ,magneto and ,functions--,transformer ,coil ,systems--,true ,high ,tension ,type--,the ,berling ,magneto--,timing and ,care--,the ,dixie ,magneto--,spark-,plug ,design and ,application--,two-,spark ,ignition--,special ,airplane ,plug #aee-bjj ,,chapter ,,vii ,why ,lubrication ,is ,necessary--,friction ,defined--,theory of ,lubrication--,derivation of ,lubricants--,properties of ,cylinder ,oils --,factors ,influencing ,lubrication ,system ,selection--,gnome ,type ,engines ,use ,castor ,oil--,hall-,scott ,lubrication ,system--,oil ,supply by ,constant ,level ,splash ,system--,dry ,crank-,case ,system ,best for ,airplane ,engines--,why ,cooling ,systems ,are ,necessary--,cooling ,systems ,generally ,applied--,cooling by ,positive ,pump ,circulation-- ,thermo-,syphon ,system--,direct ,air-,cooling ,methods--,air-,cooled ,engine ,design ,considerations #bja-bcb ,,chapter ,,viii ,methods of ,cylinder ,construction--,block ,castings--,influence on ,crank-,shaft ,design--,combustion ,chamber ,design--,bore and ,stroke ,ratio--,meaning of ,piston ,speed--,advantage of ,off-,set ,cylinders-- ,valve ,location of ,vital ,import--,valve ,installation ,practice--,valve ,design and ,construction--,valve ,operation--,methods of ,driving ,cam-,shaft--,valve ,springs--,valve ,timing--,blowing ,back--,lead ,given ,exhaust ,valve--,exhaust ,closing1 ,inlet ,opening--,closing the ,inlet ,valve--,time of ,ignition--,how an ,engine is ,timed--,gnome ,monosoupape ,valve ,timing--,springless ,valves--,four ,valves per ,cylinder #bcc-bhf ,,chapter ,,ix ,constructional ,details of ,pistons--,aluminum ,cylinders and ,pistons --,piston ,ring ,construction--,leak ,proof ,piston ,rings--,keeping ,oil ,out of ,combustion ,chamber--,connecting ,rod ,forms--,connecting ,rods for ,vee ,engines--,cam-,shaft and ,crank-,shaft ,designs--,ball ,bearing ,crank-,shafts--,engine ,base ,construction #bhg-cbc ,,chapter ,x ,power ,plant ,installation--,curtiss ,,ox-#b ,engine ,mounting and ,operating ,rules--,standard ,s4 ,a4 ,e4 ,engine ,bed ,dimensions-- ,hall-,scott ,engine ,installation and ,operation--,fuel ,system ,rules --,ignition ,system--,water ,system--,preparations to ,start ,engine-- ,mounting ,radial and ,rotary ,engines--,practical ,hints to ,locate ,engine ,troubles--,all ,engine ,troubles ,summarized--,location of ,engine ,troubles ,made ,easy #cbd-cge ,,chapter ,,xi ,tools for ,adjusting and ,erecting--,forms of ,wrenches--,use and ,care of ,files--,split ,pin ,removal and ,installation--,complete ,chisel ,set --,drilling ,machines--,drills1 ,reamers1 ,taps and ,dies--,measuring ,tools--,micrometer ,calipers and ,their ,use--,typical ,tool ,outfits --,special ,hall-,scott ,tools--,overhauling ,airplane ,engines--,taking ,engine ,down--,defects in ,cylinders--,carbon ,deposits1 ,cause and ,prevention--,use of ,carbon ,scrapers--,burning ,out ,carbon with ,oxygen --,repairing ,scored ,cylinders--,valve ,removal and ,inspection --,reseating and ,truing ,valves--,valve ,grinding ,processes-- ,depreciation in ,valve ,operating ,system--,piston ,troubles--,piston ,ring ,manipulation--,fitting ,piston ,rings--,wrist-,pin ,wear-- ,inspection and ,refitting of ,engine ,bearings--,scraping ,brasses to ,fit--,fitting ,connecting ,rods--,testing for ,bearing ,parallelism-- ,cam-,shafts and ,timing ,gears--,precautions in ,reassembling ,parts #cgf-def ,,chapter ,,xii ,aviation ,engine ,types--,division in ,classes--,anzani ,engines--,canton and ,unne ,engine--,construction of ,gnome ,engines--,monosoupape ,gnome--,german ,gnome ,type--,le ,rhone ,engine--,renault ,air-,cooled ,engine--,simplex ,model ,a ,hispano-,suiza--,curtiss ,aviation ,motors-- ,thomas-,morse ,model #hh ,engine--,duesenberg ,engine--,aeromarine ,six-,cylinder--,wisconsin ,aviation ,engines--,hall-,scott ,engines-- ,mercedes ,motor--,benz ,motor--,austro-,daimler ,engine--,sunbeam-,coatalen --,indicating and ,measuring ,instruments--,air ,starting ,systems-- ,electric ,starting--,battery ,ignition #deg-ega ,,index #egc ,,list ,,of ,,illustrations ,,aviation ,,engines ,,design--,,construction--,,repair ,,chapter ,i ,brief ,consideration of ,aircraft ,types--,essential ,requirements of ,aerial ,motors--,aviation ,engines ,must ,be ,light--,factors ,influencing ,power ,needed--,why ,explosive ,motors ,are ,best-- ,historical--,main ,types of ,internal ,combustion ,engines4 ,,brief ,,consideration ,,of ,,aircraft ,,types ,the conquest of the air is one of the most stupendous achievements of the ages4 ,human flight opens the sky to man as a new road1 and because it is a road free of all obstructions and leads everywhere1 affording the shortest distance to any place1 it offers to man the prospect of unlimited freedom4 ,the aircraft promises to span continents like railroads1 to bridge seas like ships1 to go over mountains and forests like birds1 and to quicken and simplify the problems of transportation4 ,while the actual conquest of the air is an accomplishment just being realized in our days1 the idea and yearning to conquer the air are old1 possibly as old as intellect itself4 ,the myths of different races tell of winged gods and flying men1 and show that for ages to fly was the highest conception of the sublime4 ,no other agent is more responsible for sustained flight than the internal combustion motor1 and it was only when this form of prime mover had been fully developed that it was possible for man to leave the ground and alight at will1 not depending upon the caprices of the winds or lifting power of gases as with the balloon4 ,it is safe to say that the solution of the problem of flight would have been attained many years ago if the proper source of power had been available as all the essential elements of the modern aeroplane and dirigible balloon1 other than the power plant1 were known to early philosophers and scientists4 ,aeronautics is divided into two fundamentally different branches--aviatics and aerostatics4 ,the first comprises all types of aeroplanes and heavier than air flying machines such as the helicopters1 kites1 etc42 the second includes dirigible balloons1 passive balloons and all craft which rise in the air by utilizing the lifting force of gases4 ,aeroplanes are the only practical form of heavier-than-air machines1 as the helicopters 7machines intended to be lifted directly into the air by propellers1 without the sustaining effect of planes71 and ornithopters1 or flapping wing types1 have not been thoroughly developed1 and in fact1 there are so many serious mechanical problems to be solved before either of these types of air craft will function properly that experts express grave doubts regarding the practicability of either4 ,aeroplanes are divided into two main types--monoplanes or single surface forms1 and bi-planes or machines having two sets of lifting surfaces1 one suspended over the other4 ,a third type1 the triplane1 is not very widely used4 ,dirigible balloons are divided into three classes3 the rigid1 the semi-rigid1 and the non-rigid4 ,the rigid has a frame or skeleton of either wood or metal inside of the bag1 to stiffen it2 the semi-rigid is reinforced by a wire net and metal attachments2 while the non-rigid is just a bag filled with gas4 ,the aeroplane1 more than the dirigible and balloon1 stands as the emblem of the conquest of the air4 ,two reasons for this are that power flight is a real conquest of the air1 a real victory over the battling elements2 secondly1 because the aeroplane1 or any flying machine that may follow1 brings air travel within the reach of everybody4 ,in practical development1 the dirigible may be the steamship of the air1 which will render invaluable services of a certain kind1 and the aeroplane will be the automobile of the air1 to be used by the multitude1 perhaps for as many purposes as the automobile is now being used4 ,,essential ,,requirements ,,of ,,aerial ,,motors ,one of the marked features of aircraft development has been the effect it has had upon the refinement and perfection of the internal combustion motor4 ,without question gasoline-motors intended for aircraft are the nearest to perfection of any other type yet evolved4 ,because of the peculiar demands imposed upon the aeronautical motor it must possess all the features of reliability1 economy and efficiency now present with automobile or marine engines and then must have distinctive points of its own4 ,owing to the unstable nature of the medium through which it is operated and the fact that heavier-than-air machines can maintain flight only as long as the power plant is functioning properly1 an airship motor must be more reliable than any used on either land or water4 ,while a few pounds of metal more or less makes practically no difference in a marine motor and has very little effect upon the speed or hill-climbing ability of an automobile1 an airship motor must be as light as it is possible to make it because every pound counts1 whether the motor is to be fitted into an aeroplane or in a dirigible balloon4 ,airship motors1 as a rule1 must operate constantly at high speeds in order to obtain a maximum power delivery with a minimum piston displacement4 ,in automobiles1 or motor boats1 motors are not required to run constantly at their maximum speed4 ,most aircraft motors must function for extended periods at speed as nearly the maximum as possible4 ,another thing that militates against the aircraft motor is the more or less unsteady foundation to which it is attached4 ,the necessarily light framework of the aeroplane makes it hard for a motor to perform at maximum efficiency on account of the vibration of its foundation while the craft is in flight4 ,marine and motor car engines1 while not placed on foundations as firm as those provided for stationary power plants1 are installed on bases of much more stability than the light structure of an aeroplane4 ,the aircraft motor1 therefore1 must be balanced to a nicety and must run steadily under the most unfavorable conditions4 ,,aerial ,,motors ,,must ,,be ,,light ,the capacity of light motors designed for aerial work per unit of mass is surprising to those not fully conversant with the possibilities that a thorough knowledge of proportions of parts and the use of special metals developed by the automobile industry make possible4 ,activity in the development of light motors has been more pronounced in ,france than in any other country4 ,some of these motors have been complicated types made light by the skillful proportioning of parts1 others are of the refined simpler form modified from current automobile practice4 ,there is a tendency to depart from the freakish or unconventional construction and to adhere more closely to standard forms because it is necessary to have the parts of such size that every quality making for reliability1 efficiency and endurance are incorporated in the design4 ,aeroplane motors range from two cylinders to forms having fourteen and sixteen cylinders and the arrangement of these members varies from the conventional vertical tandem and opposed placing to the ,v form or the more unusual radial motors having either fixed or rotary cylinders4 ,the weight has been reduced so it is possible to obtain a complete power plant of the revolving cylinder air-cooled type that will not weigh more than three pounds per actual horse-power and in some cases less than this4 ,if we give brief consideration to the requirements of the aviator it will be evident that one of the most important is securing maximum power with minimum mass1 and it is desirable to conserve all of the good qualities existing in standard automobile motors4 ,these are certainty of operation1 good mechanical balance and uniform delivery of power--fundamental conditions which must be attained before a power plant can be considered practical4 ,there are in addition1 secondary considerations1 none the less desirable1 if not absolutely essential4 ,these are minimum consumption of fuel and lubricating oil1 which is really a factor of import1 for upon the economy depends the capacity and flying radius4 ,as the amount of liquid fuel must be limited the most suitable motor will be that which is powerful and at the same time economical4 ,another important feature is to secure accessibility of components in order to make easy repair or adjustment of parts possible4 ,it is possible to obtain sufficiently light-weight motors without radical departure from established practice4 ,water-cooled power plants have been designed that will weigh but four or five pounds per horse-power and in these forms we have a practical power plant capable of extended operation4 ,,factors ,,influencing ,,power ,,needed ,work is performed whenever an object is moved against a resistance1 and the amount of work performed depends not only on the amount of resistance overcome but also upon the amount of time utilized in accomplishing a given task4 ,work is measured in horse-power for convenience4 ,it will take one horse-power to move #cc1jjj pounds one foot in one minute or #eej pounds one foot in one second4 ,the same work would be done if #ccj pounds were moved #ajj feet in one minute4 ,it requires a definite amount of power to move a vehicle over the ground at a certain speed1 so it must take power to overcome resistance of an airplane in the air4 ,disregarding the factor of air density1 it will take more power as the speed increases if the weight or resistance remains constant1 or more power if the speed remains constant and the resistance increases4 ,the airplane is supported by air reaction under the planes or lifting surfaces and the value of this reaction depends upon the shape of the aerofoil1 the amount it is tilted and the speed at which it is drawn through the air4 ,the angle of incidence or degree of wing tilt regulates the power required to a certain degree as this affects the speed of horizontal flight as well as the resistance4 ,resistance may be of two kinds1 one that is necessary and the other that it is desirable to reduce to the lowest point possible4 ,there is the wing resistance and the sum of the resistances of the rest of the machine such as fuselage1 struts1 wires1 landing gear1 etc4 ,if we assume that a certain airplane offered a total resistance of #cjj pounds and we wished to drive it through the air at a speed of sixty miles per hour1 we can find the horse-power needed by a very simple computation as follows3 ,the product of #cjj pounds resistance times speed of #hh feet per second times #fj seconds in a minute ---------------------------------------- ------------- ,h4,p4 needed4 divided by #cc1jjj foot pounds per minute in one horse-power ,the result is the horse-power needed1 or #cjj x #hh x #fj --------------- #dh ,h4,p4 #cc1jjj ,just as it takes more power to climb a hill than it does to run a car on the level1 it takes more power to climb in the air with an airplane than it does to fly on the level4 ,the more rapid the climb1 the more power it will take4 ,if the resistance remains #cjj pounds and it is necessary to drive the plane at #ij miles per hour1 we merely substitute proper values in the above formula and we have #cjj pounds times #acb feet per second times #fj seconds in a minute ---------------------------------------- ------- #gb ,h4,p4 #cc1jjj foot pounds per minute in one horse-power ,the same results can be obtained by dividing the product of the resistance in pounds times speed in feet per second by #eej1 which is the foot-pounds of work done in one second to equal one horse-power4 ,naturally1 the amount of propeller thrust measured in pounds necessary to drive an airplane must be greater than the resistance by a substantial margin if the plane is to fly and climb as well4 ,the following formulae were given in ,the ,aeroplane of ,london and can be used to advantage by those desiring to make computations to ascertain power requirements3 ,illustration3 ,fig4 #a4--;,diagrams ,illustrating ,computations for ,horse-,power ,required for ,airplane ,flight4 ,the thrust of the propeller depends on the power of the motor1 and on the diameter and pitch of the propeller4 ,if the required thrust to a certain machine is known1 the calculation for the horse-power of the motor should be an easy matter4 ,the required thrust is the sum of three different resistances4 ,the first is the drift 7dynamical head resistance of the aerofoils71 i4e41 tan alpha x lift 7,l71 lift being equal to the total weight of machine 7,w7 for horizontal flight and alpha equal to the angle of incidence4 ,certainly we must take the tan alpha at the maximum ,ky value for minimum speed1 as then the drift is the greatest 7,fig4 #a1 ,a74 ,another method for finding the drift is ,d ,k x ,,av#b1 when we take the drift again so as to be greatest4 ,the second resistance is the total head resistance of the machine1 at its maximum velocity4 ,and the third is the thrust for climbing4 ,the horse-power for climbing can be found out in two different ways4 ,i first propose to deal with the method1 where we find out the actual horse-power wanted for a certain climbing speed to our machine1 where climbing speed_/sec4 x ,w ,h4,p4 --------------------------- #eej ,in this case we know already the horse-power for climbing1 and we can proceed with our calculation4 ,with the other method we shall find out the thrust in pounds or kilograms wanted for climbing and add it to drift and total head resistance1 and we shall have the total thrust of our machine and we shall denote it with ,t1 while thrust for climbing shall be ,tc4 ,the following calculation is at our service to find out ,vc x ,w this thrust for climbing --------------- ,h4,p41 #eej ,h4,p4 x #eej thence ,vc ------------ 7#a7 ,w ,tc x ,v ,h4,p4 --------------1 then from #eej ,tc x ,v --------------- x #eej #eej ,tc x ,v 7#a7 ,vc ----------------------- ---------------1 thence1 ,w ,w ,vc x ,w ,tc ---------------4 ,v ,whether ,t means drifts1 head resistance and thrust for climbing1 or drift and head resistance only1 the following calculation is the same1 only in the latter case1 of course1 we must add the horse-power required for climbing to the result to obtain the total horse-power4 ,now1 when we know the total thrust1 we shall find the horse-power in the following manner3 ,pr#bpi,r ,we know that the ,h4,p4 -------------- in kilograms1 or in #ge x #fj ,pr#bpi,r ,english measure1 ,h4,p4 -------------- 7,fig4 #a1 ,b7 #cc1jjj where ,p pressure in klgs4 or lbs4 r radius on which ,p is acting4 ,r ,revolution_/min4 ,m4,r4#bpi ,when ,p x r ,m1 then ,h4,p4 -------------1 thence1 #d1ejj ,h4,p4 x #d1ejj #gaf4b ,h4,p4 ,m -------------- ------------ in meter kilograms1 ,r#bpi ,r ,h4,p4 #cc1jjj #ebec4a ,h4,p4 or in ,english system ,m ------------- ------------- in ,r#bpi ,r foot pounds4 ,now the power on the circumference of the propeller will be reduced by its radius1 so it will be ,m_/r p4 ,a part of p will be used for counteracting the air and bearing friction1 so that the total power on the circumference of the propeller will be 7,m_/r7 x eta p where eta is the mechanical efficiency of the propeller4 ,now eta --------------- ,t1 where alpha is taken on the tip of the tan alpha propeller4 ,i take alpha at the tip1 but it can be taken1 of course1 at any point1 but then in equation p ,m_/r1 r must be taken only up to this point1 and not the whole radius2 but it is more comfortable to take it at the tip1 as ,pitch tan alpha ---------- 7,fig4 #a1 ,c74 r#bpi ,now we can write up the equation of the thrust3 #gaf4b ,h4,p4 eta #ebec4a ,h4,p4 eta -------------------1 or in ,english measure ------------------- ,r r tan alpha ,r r tan alpha ,t x ,r x r tan alpha thence ,h4,p4 -----------------------------1 or in ,english measure #gaf4b;eta ,t x ,r x r tan alpha -----------------------------4 #ebec4a;eta ,the computations and formulae given are of most value to the student engineer rather than matters of general interest1 but are given so that a general idea may be secured of how airplane design influences power needed to secure sustained flight4 ,it will be apparent that the resistance of an airplane depends upon numerous considerations of design which require considerable research in aerodynamics to determine accurately4 ,it is obvious that the more resistance there is1 the more power needed to fly at a given speed4 ,light monoplanes have been flown with as little as #ae horse-power for short distances1 but most planes now built use engines of #ajj horse-power or more4 ,giant airplanes have been constructed having #b1jjj horse-power distributed in four power units4 ,the amount of power provided for an airplane of given design varies widely as many conditions govern this1 but it will range from approximately one horse-power to each #h pounds weight in the case of very light1 fast machines to one horse-power to #ae or #ah pounds of the total weight in the case of medium speed machines4 ,the development in airplane and power plant design is so rapid1 however1 that the figures given can be considered only in the light of general averages rather than being typical of current practice4 ,,why ,,explosive ,,motors ,,are ,,best ,internal combustion engines are best for airplanes and all types of aircraft for the same reasons that they are universally used as a source of power for automobiles4 ,the gasoline engine is the lightest known form of prime mover and a more efficient one than a steam engine1 especially in the small powers used for airplane propulsion4 ,it has been stated that by very careful designing a steam plant an engine could be made that would be practical for airplane propulsion1 but even with the latest development it is doubtful if steam power can be utilized in aircraft to as good advantage as modern gasoline-engines are4 ,while the steam-engine is considered very much simpler than a gas-motor1 the latter is much more easily mastered by the non-technical aviator and certainly requires less attention4 ,a weight of #aj pounds per horse-power is possible in a condensing steam plant but this figure is nearly double or triple what is easily secured with a gas-motor which may weigh but #e pounds per horse-power in the water cooled forms and but #b or #c pounds in the air-cooled types4 ,the fuel consumption is twice as great in a steam-power plant 7owing to heat losses7 as would be the case in a gasoline engine of equal power and much less weight4 ,the internal-combustion engine has come seemingly like an avalanche of a decade2 but it has come to stay1 to take its well-deserved position among the powers for aiding labor4 ,its ready adaptation to road1 aerial and marine service has made it a wonder of the age in the development of speed not before dreamed of as a possibility2 yet in so short a time1 its power for speed has taken rank on the common road against the locomotive on the rail with its century's progress4 ,it has made aerial navigation possible and practical1 it furnishes power for all marine craft from the light canoe to the transatlantic liner4 ,it operates the machine tools of the mechanic1 tills the soil for the farmer and provides healthful recreation for thousands by furnishing an economical means of transport by land and sea4 ,it has been a universal mechanical education for the masses1 and in its present forms represents the great refinement and development made possible by the concentration of the world's master minds on the problems incidental to internal combustion engineering4 ,,historical ,although the ideal principle of explosive power was conceived some two hundred years ago1 at which time experiments were made with gunpowder as the explosive element1 it was not until the last years of the eighteenth century that the idea took a patentable shape1 and not until about #ahbf 7,brown's gas-vacuum engine7 that a further progress was made in ,england by condensing the products of combustion by a jet of water1 thus creating a partial vacuum4 ,brown's was probably the first explosive engine that did real work4 ,it was clumsy and unwieldy and was soon relegated to its place among the failures of previous experiments4 ,no approach to active explosive effect in a cylinder was reached in practice1 although many ingenious designs were described1 until about #ahch and the following years4 ,barnett's engine in ,england was the first attempt to compress the charge before exploding4 ,from this time on to about #ahfj many patents were issued in ,europe and a few in the ,united ,states for gas-engines1 but the progress was slow1 and its practical introduction for power came with spasmodic effect and low efficiency4 ,from #ahfj on1 practical improvement seems to have been made1 and the ,lenoir motor was produced in ,france and brought to the ,united ,states4 ,it failed to meet expectations1 and was soon followed by further improvements in the ,hugon motor in ,france 7#ahfb71 followed by ,beau de ,rocha's four-cycle idea1 which has been slowly developed through a long series of experimental trials by different inventors4 ,in the hands of ,otto and ,langdon a further progress was made1 and numerous patents were issued in ,england1 ,france1 and ,germany1 and followed up by an increasing interest in the ,united ,states1 with a few patents4 ,from #ahgj improvements seem to have advanced at a steady rate1 and largely in the valve-gear and precision of governing for variable load4 ,the early idea of the necessity of slow combustion was a great drawback in the advancement of efficiency1 and the suggestion of de ,rocha in #ahfb did not take root as a prophetic truth until many failures and years of experience had taught the fundamental axiom that rapidity of action in both combustion and expansion was the basis of success in explosive motors4 ,with this truth and the demand for small and safe prime movers1 the manufacture of gas-engines increased in ,europe and ,america at a more rapid rate1 and improvements in perfecting the details of this cheap and efficient prime mover have finally raised it to the dignity of a standard motor and a dangerous rival of the steam-engine for small and intermediate powers1 with a prospect of largely increasing its individual units to many hundred1 if not to the thousand horse-power in a single cylinder4 ,the unit size in a single cylinder has now reached to about #gjj horse-power and by combining cylinders in the same machine1 powers of from #a1ejj to #b1jjj horse-power are now available for large power-plants4 ,,main ,,types ,,of ,,internal-,,combustion ,,engines ,this form of prime mover has been built in so many different types1 all of which have operated with some degree of success that the diversity in form will not be generally appreciated unless some attempt is made to classify the various designs that have received practical application4 ,obviously the same type of engine is not universally applicable1 because each class of work has individual peculiarities which can best be met by an engine designed with the peculiar conditions present in view4 ,the following tabular synopsis will enable the reader to judge the extent of the development of what is now the most popular prime mover for all purposes4 ,a4 ,internal ,combustion 7,standard ,type7 #a4 ,single ,acting 7,standard ,type7 #b4 ,double ,acting 7,for ,large ,power ,only7 #c4 ,simple 7,universal ,form7 #d4 ,compound 7,rarely ,used7 #e4 ,reciprocating ,piston 7,standard ,type7 #f4 ,turbine 7,revolving ,rotor1 not fully developed7 ,a#a4 ,two-,stroke ,cycle a4 ,two ,port b4 ,three ,port c4 ,combined ,two and ,three ,port d4 ,fourth ,port ,accelerator e4 ,differential ,piston ,type f4 ,distributor ,valve ,system ,a#b4 ,four-,stroke ,cycle a4 ,automatic ,inlet ,valve b4 ,mechanical ,inlet ,valve c4 ,poppet or ,mushroom ,valve d4 ,slide ,valve d #a4 ,sleeve ,valve d #b4 ,reciprocating ,ring ,valve d #c4 ,piston ,valve e4 ,rotary ,valves e #a4 ,disc e #b4 ,cylinder or ,barrel e #c4 ,single ,cone e #d4 ,double ,cone f4 ,two ,piston 7,balanced ,explosion7 g4 ,rotary ,cylinder1 ,fixed ,crank 7,aerial7 h4 ,fixed ,cylinder1 ,rotary ,crank 7,standard ,type7 ,a#c4 ,six-,stroke ,cycle ,b4 ,external ,combustion 7,practically ,obsolete7 a4 ,turbine1 ,revolving ,rotor b4 ,reciprocating ,piston ,,classification ,,by ,,cylinder ,,arrangement ,single ,cylinder a4 ,vertical b4 ,horizontal c4 ,inverted ,vertical ,double ,cylinder a4 ,vertical b4 ,horizontal 7,side by ,side7 c4 ,horizontal 7,opposed7 d4 #de to #ij ,degrees ,v 7,angularly ,disposed7 e4 ,horizontal ,tandem 7,double ,acting7 ,three ,cylinder a4 ,vertical b4 ,horizontal c4 ,rotary 7,cylinders ,spaced at #abj ,degrees7 d4 ,radially ,placed 7,stationary ,cylinders7 e4 ,one ,vertical1 ,one ,each ,side at an ,angle f4 ,compound 7,two ,high ,pressure1 ,one ,low ,pressure7 ,four ,cylinder a4 ,vertical b4 ,horizontal 7,side by ,side7 c4 ,horizontal 7,two ,pairs ,opposed7 d4 #de to #ij ,degrees ,v e4 ,twin ,tandem 7,double ,acting7 ,five ,cylinder a4 ,vertical 7,five ,throw ,crankshaft7 b4 ,radially ,spaced at #gb ,degrees 7,stationary7 c4 ,radially ,placed ,above ,crankshaft 7,stationary7 d4 ,placed ,around ,rotary ,crankcase 7#gb ,degrees ,spacing7 ,six ,cylinder a4 ,vertical b4 ,horizontal 7,three ,pairs ,opposed7 c4 #de to #ij ,degrees ,v ,seven ,cylinder a4 ,equally ,spaced 7,rotary7 ,eight ,cylinder a4 ,vertical b4 ,horizontal 7,four ,pairs ,opposed7 c4 #de to #ij ,degrees ,v ,nine ,cylinder a4 ,equally ,spaced 7,rotary7 ,twelve ,cylinder a4 ,vertical b4 ,horizontal 7,six ,pairs ,opposed7 c4 #de to #ij ,degrees ,v ,fourteen ,cylinder a4 ,rotary ,sixteen ,cylinder a4 #de to #ij ,degrees ,v b4 ,horizontal 7,eight ,pairs ,opposed7 ,eighteen ,cylinder a4 ,rotary ,cylinder ,illustration3 ,fig4 #b4--,plate ,showing ,heavy1 ,slow ,speed ,internal ,combustion ,engines ,used ,only for ,stationary ,power in ,large ,installations ,giving ,weight to ,horse-,power ,ratio4 ,illustration3 ,fig4 #c4--,various ,forms of ,internal ,combustion ,engines ,showing ,decrease in ,weight to ,horse-,power ,ratio with ,augmenting ,speed of ,rotation4 ,illustration3 ,fig4 #d4--;,internal ,combustion ,engine ,types of ,extremely ,fine ,construction and ,refined ,design1 ,showing ,great ,power ,outputs for ,very ,small ,weight1 a ,feature ,very ,much ,desired in ,airplane ,power ,plants4 ,of all the types enumerated above engines having less than eight cylinders are the most popular in everything but aircraft work4 ,the four-cylinder vertical is without doubt the most widely used of all types owing to the large number employed as automobile power plants4 ,stationary engines in small and medium powers are invariably of the single or double form4 ,three-cylinder engines are seldom used at the present time1 except in marine work and in some stationary forms4 ,eight- and twelve-cylinder motors have received but limited application and practically always in automobiles1 racing motor boats or in aircraft4 ,the only example of a fourteen-cylinder motor to be used to any extent is incorporated in aeroplane construction4 ,this is also true of the sixteen- and eighteen-cylinder forms and of twenty-four-cylinder engines now in process of development4 ,the duty an engine is designed for determines the weight per horse-power4 ,high powered engines intended for steady service are always of the slow speed type and consequently are of very massive construction4 ,various forms of heavy duty type stationary engines are shown at ,fig4 #b4 ,some of these engines may weigh as much as #fjj pounds per horse-power4 ,a further study is possible by consulting data given on ,figs4 #c and #d4 ,as the crank-shaft speed increases and cylinders are multiplied the engines become lighter4 ,while the big stationary power plants may run for years without attention1 airplane engines require rebuilding after about #fj to #hj hours air service for the fixed cylinder types and #dj hours or less for the rotary cylinder air-cooled forms4 ,there is evidently a decrease in durability and reliability as the weight is lessened4 ,these illustrations also permit of obtaining a good idea of the variety of forms internal combustion engines are made in4 ,,chapter ,,ii ,operating ,principles of ,two- and ,four-,stroke ,engines--,four-cycle ,action--,two-cycle ,action--,comparing ,two- and ,four-cycle ,types-- ,theory of ,gas and ,gasoline ,engine--,early ,gas-,engine ,forms-- ,isothermal ,law--,adiabatic ,law--,temperature ,computations--,heat and ,its ,work--,conversion of ,heat to ,power--,requisites for ,best ,power ,effect4 ,,operating ,,principles ,,of ,,two- ,,and ,,four-,,stroke ,,cycle ,,engines ,before discussing the construction of the various forms of internal combustion engines it may be well to describe the operating cycle of the types most generally used4 ,the two-cycle engine is the simplest because there are no valves in connection with the cylinder1 as the gas is introduced into that member and expelled from it through ports cored into the cylinder walls4 ,these are covered by the piston at a certain portion of its travel and uncovered at other parts of its stroke4 ,in the four-cycle engine the explosive gas is admitted to the cylinder through a port at the head end closed by a valve1 while the exhaust gas is expelled through another port controlled in a similar manner4 ,these valves are operated by mechanism distinct from the piston4 ,illustration3 ,fig4 #e4--,outlining ,first ,two ,strokes of ,piston in ,four-,cycle ,engine4 ,the action of the four-cycle type may be easily understood if one refers to illustrations at ,figs4 #e and #f4 ,it is called the four-stroke engine because the piston must make four strokes in the cylinder for each explosion or power impulse obtained4 ,the principle of the gas-engine of the internal combustion type is similar to that of a gun1 i4e41 power is obtained by the rapid combustion of some explosive or other quick burning substance4 ,the bullet is driven out of the gun barrel by the pressure of the gas evolved when the charge of powder is ignited4 ,the piston or movable element of the gas-engine is driven from the closed or head end to the crank end of the cylinder by a similar expansion of gases resulting from combustion4 ,the first operation in firing a gun or securing an explosion in the cylinder of the gas-engine is to fill the combustion space with combustible material4 ,this is done by a down stroke of the piston during which time the inlet valve opens to admit the gaseous charge to the cylinder interior4 ,this operation is shown at ,fig4 #e1 ,a4 ,the second operation is to compress this gas which is done by an upward stroke of the piston as shown at ,fig4 #e1 ,b4 ,when the top of the compression stroke is reached1 the gas is ignited and the piston is driven down toward the open end of the cylinder1 as indicated at ,fig4 #f1 ,c4 ,the fourth operation or exhaust stroke is performed by the return upward movement of the piston as shown at ,fig4 #f1 ,d during which time the exhaust valve is opened to permit the burnt gases to leave the cylinder4 ,as soon as the piston reaches the top of its exhaust stroke1 the energy stored in the fly-wheel rim during the power stroke causes that member to continue revolving and as the piston again travels on its down stroke the inlet valve opens and admits a charge of fresh gas and the cycle of operations is repeated4 ,illustration3 ,fig4 #f4--,outlining ,second ,two ,strokes of ,piston in ,four-,cycle ,engine4 ,illustration3 ,fig4 #g4--,sectional ,view of ,l ,head ,gasoline ,engine ,cylinder ,showing ,piston ,movements ,during ,four-,stroke ,cycle4 ,the illustrations at ,fig4 #g show how the various cycle functions take place in an ,l head type water cooled cylinder engine4 ,the sections at ,a and ,c are taken through the inlet valve1 those at ,b and ,d are taken through the exhaust valve4 ,the two-cycle engine works on a different principle1 as while only the combustion chamber end of the piston is employed to do useful work in the four-cycle engine1 both upper and lower portions are called upon to perform the functions necessary to two-cycle engine operation4 ,instead of the gas being admitted into the cylinder as is the case with the four-stroke engine1 it is first drawn into the engine base where it receives a preliminary compression prior to its transfer to the working end of the cylinder4 ,the views at ,fig4 #h should indicate clearly the operation of the two-port two-cycle engine4 ,at ,a the piston is seen reaching the top of its stroke and the gas above the piston is being compressed ready for ignition1 while the suction in the engine base causes the automatic valve to open and admits mixture from the carburetor to the crank case4 ,when the piston reaches the top of its stroke1 the compressed gas is ignited and the piston is driven down on the power stroke1 compressing the gas in the engine base4 ,illustration3 ,fig4 #h4--,showing ,two-port1 ,two-cycle ,engine ,operation4 ,when the top of the piston uncovers the exhaust port the flaming gas escapes because of its pressure4 ,a downward movement of the piston uncovers the inlet port opposite the exhaust and permits the fresh gas to bypass through the transfer passage from the engine base to the cylinder4 ,the conditions with the intake and exhaust port fully opened are clearly shown at ,fig4 #h1 ,c4 ,the deflector plate on the top of the piston directs the entering fresh gas to the top of the cylinder and prevents the main portion of the gas stream from flowing out through the open exhaust port4 ,on the next upstroke of the piston the gas in the cylinder is compressed and the inlet valve opened1 as shown at ,a to permit a fresh charge to enter the engine base4 ,illustration3 ,fig4 #i4--;,defining ,three-port1 ,two-cycle ,engine ,action4 ,the operating principle of the three-port1 two-cycle engine is practically the same as that previously described with the exception that the gas is admitted to the crank-case through a third port in the cylinder wall1 which is uncovered by the piston when that member reaches the end of its upstroke4 ,the action of the three-port form can be readily ascertained by studying the diagrams given at ,fig4 #i4 ,combination two- and three-port engines have been evolved and other modifications made to improve the action4 ,,the ,,two-,,cycle ,,and ,,four-,,cycle ,,types ,in the earlier years of explosive-motor progress was evolved the two types of motors in regard to the cycles of their operation4 ,the early attempts to perfect the two-cycle principle were for many years held in abeyance from the pressure of interests in the four-cycle type1 until its simplicity and power possibilities were demonstrated by ,mr4 ,dugald ,clerk in ,england1 who gave the principles of the two-cycle motor a broad bearing leading to immediate improvements in design1 which has made further progress in the ,united ,states1 until at the present time it has an equal standard value as a motor-power in some applications as its ancient rival the four-cycle or ,otto type1 as demonstrated by ,beau de ,rocha in #ahfb4 ,thermodynamically1 the methods of the two types are equal as far as combustion is concerned1 and compression may favor in a small degree the four-cycle type as well as the purity of the charge4 ,the cylinder volume of the two-cycle motor is much smaller per unit of power1 and the enveloping cylinder surface is therefore greater per unit of volume4 ,hence more heat is carried off by the jacket water during compression1 and the higher compression available from this tends to increase the economy during compression which is lost during expansion4 ,from the above considerations it may be safely stated that a lower temperature and higher pressure of charge at the beginning of compression is obtained in the two-cycle motor1 greater weight of charge and greater specific power of higher compression resulting in higher thermal efficiency4 ,the smaller cylinder for the same power of the two-cycle motor gives less friction surface per impulse than of the other type2 although the crank-chamber pressure may1 in a measure1 balance the friction of the four-cycle type4 ,probably the strongest points in favor of the two-cycle type are the lighter fly-wheel and the absence of valves and valve gear1 making this type the most simple in construction and the lightest in weight for its developed power4 ,yet1 for the larger power units1 the four-cycle type will no doubt always maintain the standard for efficiency and durability of action4 ,the distribution of the charge and its degree of mixture with the remains of the previous explosion in the clearance space1 has been a matter of discussion for both types of explosive motors1 with doubtful results4 ,in ,fig4 #aj1 ,a we illustrate what theory suggests as to the distribution of the fresh charge in a two-cycle motor1 and in ,fig4 #aj1 ,b what is the probable distribution of the mixture when the piston starts on its compressive stroke4 ,the arrows show the probable direction of flow of the fresh charge and burnt gases at the crucial moment4 ,illustration3 ,fig4 #aj4--;,diagrams ,contrasting ,action of ,two- and ,four-,cycle ,cylinders on ,exhaust and ,intake ,stroke4 ,in ,fig4 #aj1 ,c is shown the complete out-sweep of the products of combustion for the full extent of the piston stroke of a four-cycle motor1 leaving only the volume of the clearance to mix with the new charge and at ,d the manner by which the new charge sweeps by the ignition device1 keeping it cool and avoiding possibilities of pre-ignition by undue heating of the terminals of the sparking device4 ,thus1 by enveloping the sparking device with the pure mixture1 ignition spreads through the charge with its greatest possible velocity1 a most desirable condition in high-speed motors with side-valve chambers and igniters within the valve chamber4 ,,theory ,,of ,,the ,,gas ,,and ,,gasoline ,,engine ,the laws controlling the elements that create a power by their expansion by heat due to combustion1 when properly understood1 become a matter of computation in regard to their value as an agent for generating power in the various kinds of explosive engines4 ,the method of heating the elements of power in explosive engines greatly widens the limits of temperature as available in other types of heat-engines4 ,it disposes of many of the practical troubles of hot-air1 and even of steam-engines1 in the simplicity and directness of application of the elements of power4 ,in the explosive engine the difficulty of conveying heat for producing expansive effect by convection is displaced by the generation of the required heat within the expansive element and at the instant of its useful work4 ,the low conductivity of heat to and from air has been the great obstacle in the practical development of the hot-air engine2 while1 on the contrary1 it has become the source of economy and practicability in the development of the internal-combustion engine4 ,the action of air1 gas1 and the vapors of gasoline and petroleum oil1 whether singly or mixed1 is affected by changes of temperature practically in nearly the same ratio2 but when the elements that produce combustion are interchanged in confined spaces1 there is a marked difference of effect4 ,the oxygen of the air1 the hydrogen and carbon of a gas1 or vapor of gasoline or petroleum oil are the elements that by combustion produce heat to expand the nitrogen of the air and the watery vapor produced by the union of the oxygen in the air and the hydrogen in the gas1 as well as also the monoxide and carbonic-acid gas that may be formed by the union of the carbon of gas or vapor with part of the oxygen of the air4 ,the various mixtures as between air and gas1 or air and vapor1 with the proportion of the products of combustion left in the cylinder from a previous combustion1 form the elements to be considered in estimating the amount of pressure that may be obtained by their combustion and expansive force4 ,,early ,,gas ,,engine ,,forms ,the working process of the explosive motor may be divided into three principal types3 #a4 ,motors with charges igniting at constant volume without compression1 such as the ,lenoir1 ,hugon1 and other similar types now abandoned as wasteful in fuel and effect4 #b4 ,motors with charges igniting at constant pressure with compression1 in which a receiver is charged by a pump and the gases burned while being admitted to the motor cylinder1 such as types of the ,simon and ,brayton engine4 #c4 ,motors with charges igniting at constant volume with variable compression1 such as the later two- and four-cycle motors with compression of the indrawn charge2 limited in the two-cycle type and variable in the four-cycle type with the ratios of the clearance space in the cylinder4 ,this principle produces the explosive motor of greatest efficiency4 ,the phenomena of the brilliant light and its accompanying heat at the moment of explosion have been witnessed in the experiments of ,dugald ,clerk in ,england1 the illumination lasting throughout the stroke2 but in regard to time in a four-cycle engine1 the incandescent state exists only one-quarter of the running time4 ,thus the time interval1 together with the non-conductibility of the gases1 makes the phenomena of a high-temperature combustion within the comparatively cool walls of a cylinder a practical possibility4 ,,the ,,isothermal ,,law ,the natural laws1 long since promulgated by ,boyle1 ,gay ,lussac1 and others1 on the subject of the expansion and compression of gases by force and by heat1 and their variable pressures and temperatures when confined1 are conceded to be practically true and applicable to all gases1 whether single1 mixed1 or combined4 ,the law formulated by ,boyle only relates to the compression and expansion of gases without a change of temperature1 and is stated in these words3 ,if the temperature of a gas be kept constant1 its pressure or elastic force will vary inversely as the volume it occupies4 ,it is expressed in the formula ,p x ,v ,c1 or pressure x volume constant4 ,hence1 ,c_/,p ,v and ,c_/,v ,p4 ,thus the curve formed by increments of pressure during the expansion or compression of a given volume of gas without change of temperature is designated as the isothermal curve in which the volume multiplied by the pressure is a constant value in expansion1 and inversely the pressure divided by the volume is a constant value in compressing a gas4 ,but as compression and expansion of gases require force for their accomplishment mechanically1 or by the application or abstraction of heat chemically1 or by convection1 a second condition becomes involved1 which was formulated into a law of thermodynamics by ,gay ,lussac under the following conditions3 ,a given volume of gas under a free piston expands by heat and contracts by the loss of heat1 its volume causing a proportional movement of a free piston equal to #a_/bgc part of the cylinder volume for each degree ,centigrade difference in temperature1 or #a_/dib part of its volume for each degree ,fahrenheit4 ,with a fixed piston 7constant volume71 the pressure is increased or decreased by an increase or decrease of heat in the same proportion of #a_/bgc part of its pressure for each degree ,centigrade1 or #a_/dib part of its pressure for each degree ,fahrenheit change in temperature4 ,this is the natural sequence of the law of mechanical equivalent1 which is a necessary deduction from the principle that nothing in nature can be lost or wasted1 for all the heat that is imparted to or abstracted from a gaseous body must be accounted for1 either as heat or its equivalent transformed into some other form of energy4 ,in the case of a piston moving in a cylinder by the expansive force of heat in a gaseous body1 all the heat expended in expansion of the gas is turned into work2 the balance must be accounted for in absorption by the cylinder or radiation4 ,,the ,,adiabatic ,,law ,this theory is equally applicable to the cooling of gases by abstraction of heat or by cooling due to expansion by the motion of a piston4 ,the denominators of these heat fractions of expansion or contraction represent the absolute zero of cold below the freezing-point of water1 and read -#bgc deg4 ,c4 or -#dib4ff deg4 -#dfj4ff deg4 ,f4 below zero2 and these are the starting-points of reference in computing the heat expansion in gas-engines4 ,according to ,boyle's law1 called the first law of gases1 there are but two characteristics of a gas and their variations to be considered1 viz41 volume and pressure3 while by the law of ,gay ,lussac1 called the second law of gases1 a third is added1 consisting of the value of the absolute temperature1 counting from absolute zero to the temperatures at which the operations take place4 ,this is the ,adiabatic law4 ,the ratio of the variation of the three conditions--volume1 pressure1 and heat--from the absolute zero temperature has a certain rate1 in which the volume multiplied by the pressure and the product divided by the absolute temperature equals the ratio of expansion for each degree4 ,if a volume of air is contained in a cylinder having a piston and fitted with an indicator1 the piston1 if moved to and fro slowly1 will alternately compress and expand the air1 and the indicator pencil will trace a line or lines upon the card1 which lines register the change of pressure and volume occurring in the cylinder4 ,if the piston is perfectly free from leakage1 and it be supposed that the temperature of the air is kept quite constant1 then the line so traced is called an ,isothermal line1 and the pressure at any point when multiplied by the volume is a constant1 according to ,boyle's law1 pv a constant4 ,if1 however1 the piston is moved very rapidly1 the air will not remain at constant temperature1 but the temperature will increase because work has been done upon the air1 and the heat has no time to escape by conduction4 ,if no heat whatever is lost by any cause1 the line will be traced over and over again by the indicator pencil1 the cooling by expansion doing work precisely equalling the heating by compression4 ,this is the line of no transmission of heat1 therefore known as ,adiabatic4 ,illustration3 ,fig4 #aa4--;,diagram ,isothermal and ,adiabatic ,lines4 ,the expansion of a gas #a_/bgc of its volume for every degree ,centigrade1 added to its temperature1 is equal to the decimal 4#jjcff1 the coefficient of expansion for ,centigrade units4 ,to any given volume of a gas1 its expansion may be computed by multiplying the coefficient by the number of degrees1 and by reversing the process the degree of acquired heat may be obtained approximately4 ,these methods are not strictly in conformity with the absolute mathematical formula1 because there is a small increase in the increment of expansion of a dry gas1 and there is also a slight difference in the increment of expansion due to moisture in the atmosphere and to the vapor of water formed by the union of the hydrogen and oxygen in the combustion chamber of explosive engines4 ,,temperature ,,computations ,the ratio of expansion on the ,fahrenheit scale is derived from the absolute temperature below the freezing-point of water 7#cb deg47 to correspond with the ,centigrade scale2 therefore #a_/dib4ff 4#jjbjbig1 the ratio of expansion from #cb deg4 for each degree rise in temperature on the ,fahrenheit scale4 ,as an example1 if the temperature of any volume of air or gas at constant volume is raised1 say from #fj deg4 to #bjjj deg4 ,f41 the increase in temperature will be #aidj deg44 ,the ratio will be #a_/ebj4ff 4#jjaibjf4 ,then by the formula3 ,ratio x acquired temp4 x initial pressure the gauge pressure2 and 4#jjaibjf x #aidj deg4 x #ad4g #ed4gg lbs4 ,by another formula1 a convenient ratio is obtained by 7absolute pressure7_/7absolute temp47 or #ad4g_/ebj4ff 4#jbhbcc2 then1 using the difference of temperature as before1 4#jbhbcc x #aidj deg4 #ed4gg lbs4 pressure4 ,by another formula1 leaving out a small increment due to specific heat at high temperatures3 ,atmospheric pressure x absolute temp4 acquired temp4 ,i4 ---------------------------------------- ---------------- ,absolute temp4 initial temp4 absolute pressure due to the acquired temperature1 from which the atmospheric pressure is deducted for the gauge pressure4 ,using the foregoing example1 we have 7#ad4g x #dfj4ff deg4 #bjjj deg47_/7#dfj4ff #fj deg47 #fi4dg - #ad4g #ed4gg1 the gauge pressure1 #dfj4ff being the absolute temperature for zero ,fahrenheit4 ,for obtaining the volume of expansion of a gas from a given increment of heat1 we have the approximate formula3 ,volume x absolute temp4 acquired temp4 ,,ii4 ---------------------------------------- -- ,absolute temp4 initial temp4 heated volume4 ,in applying this formula to the foregoing example1 the figures become3 #dfj4ff deg4 #bjjj deg4 ,i4 x ------------------------- #d4gbfjd volumes4 #dfj4ff #fj deg4 ,from this last term the gauge pressure may be obtained as follows3 ,,iii4 #d4gbfjd x #ad4g #fi4dg lbs4 absolute - #ad4g lbs4 atmospheric pressure #ed4gg lbs4 gauge pressure2 which is the theoretical pressure due to heating air in a confined space1 or at constant volume from #fj deg4 to #bjjj deg4 ,f4 ,by inversion of the heat formula for absolute pressure we have the formula for the acquired heat1 derived from combustion at constant volume from atmospheric pressure to gauge pressure plus atmospheric pressure as derived from ,example ,i41 by which the expression absolute pressure x absolute temp4 initial temp4 ---------------------------------------- ------------ initial absolute pressure absolute temperature temperature of combustion1 from which the acquired temperature is obtained by subtracting the absolute temperature4 ,then1 for example1 7#fi4dg x #dfj4ff #fj7_/ad4g #bdfj4ff1 and #bdfj4ff - #dfj4ff #bjjj deg41 the theoretical heat of combustion4 ,the dropping of terminal decimals makes a small decimal difference in the result in the different formulas4 ,,heat ,,and ,,its ,,work ,by ,joule's law of the mechanical equivalent of heat1 whenever heat is imparted to an elastic body1 as air or gas1 energy is generated and mechanical work produced by the expansion of the air or gas4 ,when the heat is imparted by combustion within a cylinder containing a movable piston1 the mechanical work becomes an amount measurable by the observed pressure and movement of the piston4 ,the heat generated by the explosive elements and the expansion of the non-combining elements of nitrogen and water vapor that may have been injected into the cylinder as moisture in the air1 and the water vapor formed by the union of the oxygen of the air with the hydrogen of the gas1 all add to the energy of the work from their expansion by the heat of internal combustion4 ,as against this1 the absorption of heat by the walls of the cylinder1 the piston1 and cylinder-head or clearance walls1 becomes a modifying condition in the force imparted to the moving piston4 ,it is found that when any explosive mixture of air and gas or hydrocarbon vapor is fired1 the pressure falls far short of the pressure computed from the theoretical effect of the heat produced1 and from gauging the expansion of the contents of a cylinder4 ,it is now well known that in practice the high efficiency which is promised by theoretical calculation is never realized2 but it must always be remembered that the heat of combustion is the real agent1 and that the gases and vapors are but the medium for the conversion of inert elements of power into the activity of energy by their chemical union4 ,the theory of combustion has been the leading stimulus to large expectations with inventors and constructors of explosive motors2 its entanglement with the modifying elements in practice has delayed the best development in construction1 and as yet no really positive design of best form or action seems to have been accomplished1 although great progress has been made during the past decade in the development of speed1 reliability1 economy1 and power output of the individual units of this comparatively new power4 ,one of the most serious difficulties in the practical development of pressure1 due to the theoretical computations of the pressure value of the full heat1 is probably caused by imparting the heat of the fresh charge to the balance of the previous charge that has been cooled by expansion from the maximum pressure to near the atmospheric pressure of the exhaust4 ,the retardation in the velocity of combustion of perfectly mixed elements is now well known from experimental trials with measured quantities2 but the principal difficulty in applying these conditions to the practical work of an explosive engine where a necessity for a large clearance space cannot be obviated1 is in the inability to obtain a maximum effect from the imperfect mixture and the mingling of the products of the last explosion with the new mixture1 which produces a clouded condition that makes the ignition of the mass irregular or chattering1 as observed in the expansion lines of indicator cards2 but this must not be confounded with the reaction of the spring in the indicator4 ,stratification of the mixture has been claimed as taking place in the clearance chamber of the cylinder2 but this is not a satisfactory explanation in view of the vortical effect of the violent injection of the air and gas or vapor mixture4 ,it certainly cannot become a perfect mixture in the time of a stroke of a high-speed motor of the two-cycle class4 ,in a four-cycle engine1 making #a1ejj revolutions per minute1 the injection and compression in any one cylinder take place in one twenty-fifth of a second--formerly considered far too short a time for a perfect infusion of the elements of combustion but now very easily taken care of despite the extremely high speed of numerous aviation and automobile power-plants4 ,,table ,i4--,,explosion ,,at ,,constant ,,volume ,,in ,a ,,closed ,,chamber4 ,dia- ,temp4 ,time ,ob- ,com- gram of of served puted ,curve ,mixture ,injected4 ,injec-,explo- ,gauge ,temp4 ,fig4 tion sion ,pressure,fahr4 #h4 ,fahr4,second4 ,pounds ---------------------------------------- --------------------------- a #a volume gas to #ad volumes air4 #fd deg #j4de #dj4 #a1dhc deg4 b #a #ac #ea deg #j4ca #ea4e #a1hei deg4 c #a #ab #ea deg #j4bd #fj4 #b1aie deg4 d #a #aa #ea deg #j4ag #fa4 #b1bbh deg4 e #a #i #fb deg #j4jh #gh4 #b1hce deg4 f #a #g #fb deg #j4jf #hg4 #c1aea deg4 g #a #f #ea deg #j4jd #ij4 #c1beg deg4 h #a #e #ea deg #j4jee #ia4 #c1bic deg4 i #a #d #ff deg #j4af #hj4 #b1hga deg4 ---------------------------------------- --------------------------- ,in an examination of the times of explosion and the corresponding pressures in both tables1 it will be seen that a mixture of #a part gas to #f parts air is the most effective and will give the highest mean pressure in a gas-engine4 ,there is a limit to the relative proportions of illuminating gas and air mixture that is explosive1 somewhat variable1 depending upon the proportion of hydrogen in the gas4 ,with ordinary coal-gas1 #a of gas to #ae parts of air2 and on the lower end of the scale1 #a volume of gas to #b parts air1 are non-explosive4 ,with gasoline vapor the explosive effect ceases at #a to #af1 and a saturated mixture of equal volumes of vapor and air will not explode1 while the most intense explosive effect is from a mixture of #a part vapor to #i parts air4 ,in the use of gasoline and air mixtures from a carburetor1 the best effect is from #a part saturated air to #h parts free air4 ,,table ,,ii4--,,properties ,,and ,,explosive ,,temperature ,,of ,a ,,mixture ,,of ,,one ,,part ,,of ,,illuminating ,,gas ,,of #ffj ,,thermal ,,units ,,per ,,cubic ,,foot ,,with ,,various ,,proportions ,,of ,,air ,,without ,,mixture ,,of ,,charge ,,with ,,the ,,products ,,of ,a ,,previous ,,explosion4 ,a ,proportion1 ,air to ,gas by ,volumes4 ,b ,pounds in ,one ,cubic ,foot of ,mixture4 ,c ,specific ,heat4 ,heat ,units ,required to ,raise #a ,lb4 #a ,deg4 ,fahrenheit4 ,constant ,pressure4 ,d ,specific ,heat4 ,heat ,units ,required to ,raise #a ,lb4 #a ,deg4 ,fahrenheit4 ,constant ,volume4 ,e ,heat to ,raise ,one ,cubic ,foot of ,mixture #a ,deg4 ,fahr4 ,f ,heat ,units ,evolved by ,combustion4 ,g ,ratio ,col4 #f_/e ,h ,usual ,combustion ,efficiency4 ,i ,usual ,rise of ,temperature due to ,explosion at ,constant ,volume4 ,a ,b ,c ,d ,e ,f ,g ,h ,i ---------------------------------------- ------------------ #f to #a 4#jgdaie 4#bffh 4#aiac 4#jadahi #id4bh #ffdd4f 4#dfe #cjij #g to #a 4#jgejab 4#bfbh 4#ahhb 4#jadaaf #hb4 #ehdd4d 4#eah #cjbg #h to #a 4#jgefdg 4#beih 4#aheh 4#jadjei #gc4cc #ebaf4a 4#edc #bhcb #i to #a 4#jgfaee 4#bege 4#ahdf 4#jadjac #ff4 #dgji4i 4#ef #bfcg #aj to #a 4#jgfega 4#beee 4#ahbe 4#jacigf #fj4 #dbic4 4#ege #bdfh #aa to #a 4#jgfiag 4#bedj 4#ahac 4#jacide #ee4 #cidd4 4#ehe #bcjg #ab to #a 4#jggbaa 4#bebf 4#ahjc 4#jacibb #ej4gg #cfdf4g 4#eh #baae ---------------------------------------- ------------------ ,the weight of a cubic foot of gas and air mixture as given in ,col4 #b is found by adding the number of volumes of air multiplied by its weight1 4#jhjg1 to one volume of gas of weight 4#jce pound per cubic foot and dividing by the total number of volumes2 for example1 as in the table1 #f x 4#jhjg 4#eaib_/g 4#jgdaie as in the first line1 and so on for any mixture or for other gases of different specific weight per cubic foot4 ,the heat units evolved by combustion of the mixture 7,col4 #f7 are obtained by dividing the total heat units in a cubic foot of gas by the total proportion of the mixture1 #ffj_/g #id4bh as in the first line of the table4 ,col4 #e is obtained by multiplying the weight of a cubic foot of the mixture in ,col4 #b by the specific heat at a constant volume 7,col4 #d71 ,col4 #f_/;,col4 #e ,col4 #g the total heat ratio1 of which ,col4 #h gives the usual combustion efficiency--,col4 #g x ,col4 #h gives the absolute rise in temperature of a pure mixture1 as given in ,col4 #i4 ,the many recorded experiments made to solve the discrepancy between the theoretical and the actual heat development and resulting pressures in the cylinder of an explosive motor1 to which much discussion has been given as to the possibilities of dissociation and the increased specific heat of the elements of combustion and non-combustion1 as well1 also1 of absorption and radiation of heat1 have as yet furnished no satisfactory conclusion as to what really takes place within the cylinder walls4 ,there seems to be very little known about dissociation1 and somewhat vague theories have been advanced to explain the phenomenon4 ,the fact is1 nevertheless1 apparent as shown in the production of water and other producer gases by the use of steam in contact with highly incandescent fuel4 ,it is known that a maximum explosive mixture of pure gases1 as hydrogen and oxygen or carbonic oxide and oxygen1 suffers a contraction of one-third their volume by combustion to their compounds1 steam or carbonic acid4 ,in the explosive mixtures in the cylinder of a motor1 however1 the combining elements form so small a proportion of the contents of the cylinder that the shrinkage of their volume amounts to no more than #c per cent4 of the cylinder volume4 ,this by no means accounts for the great heat and pressure differences between the theoretical and actual effects4 ,,conversion ,,of ,,heat ,,to ,,power ,the utilization of heat in any heat-engine has long been a theme of inquiry and experiment with scientists and engineers1 for the purpose of obtaining the best practical conditions and construction of heat-engines that would represent the highest efficiency or the nearest approach to the theoretical value of heat1 as measured by empirical laws that have been derived from experimental researches relating to its ultimate volume4 ,it is well known that the steam-engine returns only from #ab to #ah per cent4 of the power due to the heat generated by the fuel1 about #be per cent4 of the total heat being lost in the chimney1 the only use of which is to create a draught for the fire2 the balance1 some #fj per cent41 is lost in the exhaust and by radiation4 ,the problem of utmost utilization of force in steam has nearly reached its limit4 ,the internal-combustion system of creating power is comparatively new in practice1 and is but just settling into definite shape by repeated trials and modification of details1 so as to give somewhat reliable data as to what may be expected from the rival of the steam-engine as a prime mover4 ,for small powers1 the gas1 gasoline1 and petroleum-oil engines are forging ahead at a rapid rate1 filling the thousand wants of manufacture and business for a power that does not require expensive care1 that is perfectly safe at all times1 that can be used in any place in the wide world to which its concentrated fuel can be conveyed1 and that has eliminated the constant handling of crude fuel and water4 ,,requisites ,,for ,,best ,,power ,,effect ,the utilization of heat in a gas-engine is mainly due to the manner in which the products entering into combustion are distributed in relation to the movement of the piston4 ,the investigation of the foremost exponent of the theory of the explosive motor was prophetic in consideration of the later realization of the best conditions under which these motors can be made to meet the requirements of economy and practicability4 ,as early as #ahfb1 ,beau de ,rocha announced1 in regard to the coming power1 that four requisites were the basis of operation for economy and best effect4 #a4 ,the greatest possible cylinder volume with the least possible cooling surface4 #b4 ,the greatest possible rapidity of expansion4 ,hence1 high speed4 #c4 ,the greatest possible expansion4 ,long stroke4 #d4 ,the greatest possible pressure at the commencement of expansion4 ,high compression4 ,,chapter ,,iii ,efficiency of ,internal ,combustion ,engines--,various ,measures of ,efficiency--,temperatures and ,pressures--,factors ,governing ,economy--,losses in ,wall ,cooling--,value of ,indicator ,cards-- ,compression in ,explosive ,motors--,factors ,limiting ,compression-- ,causes of ,heat ,losses and ,inefficiency--,heat ,losses to ,cooling ,water4 ,,efficiency ,,of ,,internal ,,combustion ,,engines ,efficiencies are worked out through intricate formulas for a variety of theoretical and unknown conditions of combustion in the cylinder3 ratios of clearance and cylinder volume1 and the uncertain condition of the products of combustion left from the last impulse and the wall temperature4 ,but they are of but little value1 except as a mathematical inquiry as to possibilities4 ,the real commercial efficiency of a gas or gasoline-engine depends upon the volume of gas or liquid at some assigned cost1 required per actual brake horse-power per hour1 in which an indicator card should show that the mechanical action of the valve gear and ignition was as perfect as practicable1 and that the ratio of clearance1 space1 and cylinder volume gave a satisfactory terminal pressure and compression3 i4e41 the difference between the power figured from the indicator card and the brake power being the friction loss of the engine4 ,in four-cycle motors of the compression type1 the efficiencies are greatly advanced by compression1 producing a more complete infusion of the mixture of gas or vapor and air1 quicker firing1 and far greater pressure than is possible with the two-cycle type previously described4 ,in the practical operation of the gas-engine during the past twenty years1 the gas-consumption efficiencies per indicated horse-power have gradually risen from #ag per cent4 to a maximum of #dj per cent4 of the theoretical heat1 and this has been done chiefly through a decreased combustion chamber and increased compression--the compression having gradually increased in practice from #cj lbs4 per square inch to above #ajj2 but there seems to be a limit to compression1 as the efficiency ratio decreases with greater increase in compression4 ,it has been shown that an ideal efficiency of #cc per cent4 for #ch lbs41 compression will increase to #dj per cent4 for #ff lbs41 and #dc per cent4 for #hh lbs4 compression4 ,on the other hand1 greater compression means greater explosive pressure and greater strain on the engine structure1 which will probably retain in future practice the compression between the limits of #dj and #ij lbs4 except in super-compression engines intended for high altitude work where compression pressures as high as #abe pounds have been used4 ,in experiments made by ,dugald ,clerk1 in ,england1 with a combustion chamber equal to #j4f of the space swept by the piston1 with a compression of #ch lbs41 the consumption of gas was #bd cubic feet per indicated horse-power per hour4 ,with #j4d compression space and #fa lbs4 compression1 the consumption of gas was #bj cubic feet per indicated horse-power per hour2 and with #j4cd compression space and #hg lbs4 compression1 the consumption of gas fell to #ad4h cubic feet per indicated horse-power per hour--the actual efficiencies being respectively #ag1 #ba1 and #be per cent4 ,this was with a ,crossley four-cycle engine4 ,,various ,,measures ,,of ,,efficiency ,the efficiencies in regard to power in a heat-engine may be divided into four kinds1 as follows3 ,i4 ,the first is known as the maximum theoretical efficiency of a perfect engine 7represented by the lines in the indicator diagram74 ,it is expressed by the formula 7,t#a - ,t#j7_/,t#a and shows the work of a perfect cycle in an engine working between the received temperature absolute temperature 7,t#a7 and the initial atmospheric temperature absolute temperature 7,t#j74 ,,ii4 ,the second is the actual heat efficiency1 or the ratio of the heat turned into work to the total heat received by the engine4 ,it expresses the indicated horse-power4 ,,iii4 ,the third is the ratio between the second or actual heat efficiency and the first or maximum theoretical efficiency of a perfect cycle4 ,it represents the greatest possible utilization of the power of heat in an internal-combustion engine4 ,,iv4 ,the fourth is the mechanical efficiency4 ,this is the ratio between the actual horse-power delivered by the engine through a dynamometer or measured by a brake 7brake horse-power71 and the indicated horse-power4 ,the difference between the two is the power lost by engine friction4 ,in regard to the general heat efficiency of the materials of power in explosive engines1 we find that with good illuminating gas the practical efficiency varies from #be to #dj per cent42 kerosene-motors1 #bj to #cj2 gasoline-motors1 #bj to #cb2 acetylene1 #be to #ce2 alcohol1 #bj to #cj per cent4 of their heat value4 ,the great variation is no doubt due to imperfect mixtures and variable conditions of the old and new charge in the cylinder2 uncertainty as to leakage and the perfection of combustion4 ,in the ,diesel motors operating under high pressure1 up to nearly #ejj pounds1 an efficiency of #cf per cent4 is claimed4 ,illustration3 ,fig4 #ab4--;,graphic ,diagram ,showing ,approximate ,utilization of ,fuel ,burned in ,internal-,combustion ,engine4 ,the graphic diagram at ,fig4 #ab is of special value as it shows clearly how the heat produced by charge combustion is expended in an engine of average design4 ,on general principles the greater difference between the heat of combustion and the heat at exhaust is the relative measure of the heat turned into work1 which represents the degree of efficiency without loss during expansion4 ,the mathematical formulas appertaining to the computation of the element of heat and its work in an explosive engine are in a large measure dependent upon assumed values1 as the conditions of the heat of combustion are made uncertain by the mixing of the fresh charge with the products of a previous combustion1 and by absorption1 radiation1 and leakage4 ,the computation of the temperature from the observed pressure may be made as before explained1 but for compression-engines the needed starting-points for computation are very uncertain1 and can only be approximated from the exact measure and value of the elements of combustion in a cylinder charge4 ,,temperatures ,,and ,,pressures ,owing to the decrease from atmospheric pressure in the indrawing charge of the cylinder1 caused by valve and frictional obstruction1 the compression seldom starts above #ac lbs4 absolute1 especially in high-speed engines4 ,col4 #c in the following table represents the approximate absolute compression pressure for the clearance percentage and ratio in ,cols4 #a and #b1 while ,col4 #d indicates the gauge pressure from the atmospheric line4 ,the temperatures in ,col4 #e are due to the compression in ,col4 #c from an assumed temperature of #efj deg4 ,f4 in the mixture of the fresh charge of #f air to #a gas with the products of combustion left in the clearance chamber from the exhaust stroke of a medium-speed motor4 ,this temperature is subject to considerable variation from the difference in the heat-unit power of the gases and vapors used for explosive power1 as also of the cylinder-cooling effect4 ,in ,col4 #f is given the approximate temperatures of explosion for a mixture of air #f to gas #a of #ffj heat units per cubic foot1 for the relative values of the clearance ratio in ,col4 #b at constant volume4 ,,table ,,iii4--,,gas-,,engine ,,clearance ,,ratios1 ,,approximate ,,compression1 ,,temperatures ,,of ,,explosion ,,and ,,explosive ,,pressures ,,with ,a ,,mixture ,,of ,,gas ,,of #ffj ,,heat ,,units ,,per ,,cubic ,,foot ,,and ,,mixture ,,of ,,gas #a ,,to #f ,,of ,,air4 ,a ,clearance ,per ,cent4 of ,piston ,volume4 ,b ,ratio 7,v_/,vc7 7,p ,c ,vol47_/,clearance ,c ,approximate ,compression from #ac ,pounds ,absolute4 ,d ,approximate ,gauge ,pressure4 ,e ,absolute ,temperature of ,compression from #efj ,deg4 ,fahrenheit in ,cylinder4 ,f ,absolute ,temperature of ,explosion4 ,gas1 #a part2 ,air1 #f parts4 ,g ,approximate ,explosion ,pressure ,absolute4 ,h ,approximate ,gauge ,pressure4 ,i ,approximate ,temperature of ,explosion1 ,fahrenheit4 ,a ,b ,c ,d ,e ,f ,g ,h ,i ---------------------------------------- --------- #a #b #c #d #e #f #g #h #i ---------------------------------------- --------- ,lbs4 ,deg4 ,deg4 ,lbs4 ,lbs4 ,deg4 4#ej #c4 #eg4 #db4 #hbb4 #bdhh #afi #add #bjbg 4#ddd #c4be #fe4 #ej4 #hdf4 #befh #aig #ahb #bajg 4#dj #c4ej #gj4 #ee4 #hfh4 #bfch #bab #aig #bagg 4#cfc #c4ge #gg4 #fb4 #hhi4 #bgja #bcd #bai #bbdj 4#ccc #d4 #hd4 #fi4 #iaj4 #bgea #bed #bci #bbij 4#bhe #d4ej #ajb4 #hh4 #iee4 #bhdb #cjc #bhh #bcha 4#be #e4 #aad4 #ii4 #ihc4 #bija #ccf #cba #bddj ---------------------------------------- --------- ,,factors ,,governing ,,economy ,in view of the experiments in this direction1 it clearly shows that in practical work1 to obtain the greatest economy per effective brake horse-power1 it is necessary3 #ast4 ,to transform the heat into work with the greatest rapidity mechanically allowable4 ,this means high piston speed4 #b;d4 ,to have high initial compression4 #c;d4 ,to reduce the duration of contact between the hot gases and the cylinder walls to the smallest amount possible2 which means short stroke and quick speed1 with a spherical cylinder head4 #dth4 ,to adjust the temperature of the jacket water to obtain the most economical output of actual power4 ,this means water-tanks or water-coils1 with air-cooling surfaces suitable and adjustable to the most economical requirement of the engine1 which by late trials requires the jacket water to be discharged at about #bjj deg4 ,f4 #eth4 ,to reduce the wall surface of the clearance space or combustion chamber to the smallest possible area1 in proportion to its required volume4 ,this lessens the loss of the heat of combustion by exposure to a large surface1 and allows of a higher mean wall temperature to facilitate the heat of compression4 ,,losses ,,in ,,wall ,,cooling ,in an experimental investigation of the efficiency of a gas-engine under variable piston speeds made in ,france1 it was found that the useful effect increases with the velocity of the piston--that is1 with the rate of expansion of the burning gases with mixtures of uniform volumes3 so that the variations of time of complete combustion at constant pressure1 and the variations due to speed1 in a way compensate in their efficiencies4 ,the dilute mixture1 being slow burning1 will have its time and pressure quickened by increasing the speed4 ,careful trials give unmistakable evidence that the useful effect increases with the velocity of the piston--that is1 with the rate of expansion of the burning gases4 ,the time necessary for the explosion to become complete and to attain its maximum pressure depends not only on the composition of the mixture1 but also upon the rate of expansion4 ,this has been verified in experiments with a high-speed motor1 at speeds from #ejj to #b1jjj revolutions per minute1 or piston speeds of from #af to #fd feet per second4 ,the increased speed of combustion due to increased piston speed is a matter of great importance to builders of gas-engines1 as well as to the users1 as indicating the mechanical direction of improvements to lessen the wearing strain due to high speed and to lighten the vibrating parts with increased strength1 in order that the balancing of high-speed engines may be accomplished with the least weight4 ,from many experiments made in ,europe and in the ,united ,states1 it has been conclusively proved that excessive cylinder cooling by the water-jacket results in a marked loss of efficiency4 ,in a series of experiments with a simplex engine in ,france1 it was found that a saving of #g per cent4 in gas consumption per brake horse-power was made by raising the temperature of the jacket water from #ada deg4 to #afe deg4 ,f4 ,a still greater saving was made in a trial with an ,otto engine by raising the temperature of the jacket water from #fa deg4 to #adj deg4 ,f4--it being #i4e per cent4 less gas per brake horse-power4 ,it has been stated that volumes of similar cylinders increase as the cube of their diameters1 while the surface of their cold walls varies as the square of their diameters2 so that for large cylinders the ratio of surface to volume is less than for small ones4 ,this points to greater economy in the larger engines4 ,the study of many experiments goes to prove that combustion takes place gradually in the gas-engine cylinder1 and that the rate of increase of pressure or rapidity of firing is controlled by dilution and compression of the mixture1 as well as by the rate of expansion or piston speed4 ,the rate of combustion also depends on the size and shape of the explosion chamber1 and is increased by the mechanical agitation of the mixture during combustion1 and still more by the mode of firing4 ,,value ,,of ,,indicator ,,cards ,illustration3 ,fig4 #ac4--,otto ,four-,cycle ,card4 ,to the uninitiated1 indicator cards are considerable of a mystery2 to those capable of reading them they form an index relative to the action of any engine4 ,an indicator card1 such as shown at ,fig4 #ac1 is merely a graphical representation of the various pressures existing in the cylinder for different positions of the piston4 ,the length is to some scale that represents the stroke of the piston4 ,during the intake stroke1 the pressure falls below the atmospheric line4 ,during compression1 the curve gradually becomes higher owing to increasing pressure as the volume is reduced4 ,after ignition the pressure line moves upward almost straight1 then as the piston goes down on the explosion stroke1 the pressure falls gradually to the point of exhaust valve1 opening when the sudden release of the imprisoned gas causes a reduction in pressure to nearly atmospheric4 ,an indicator card1 or a series of them1 will always show by its lines the normal or defective condition of the inlet valve and passages2 the actual line of compression2 the firing moment2 the pressure of explosion2 the velocity of combustion2 the normal or defective line of expansion1 as measured by the adiabatic curve1 and the normal or defective operation of the exhaust valve1 exhaust passages1 and exhaust pipe4 ,in fact1 all the cycles of an explosive motor may be made a practical study from a close investigation of the lines of an indicator card4 ,illustration3 ,fig4 #ad4--;,diesel ,motor ,card4 ,a most unique card is that of the ,diesel motor 7,fig4 #ad71 which involves a distinct principle in the design and operation of internal-combustion motors1 in that instead of taking a mixed charge for instantaneous explosion1 its charge primarily is of air and its compression to a pressure at which a temperature is attained above the igniting point of the fuel1 then injecting the fuel under a still higher pressure by which spontaneous combustion takes place gradually with increasing volume over the compression for part of the stroke or until the fuel charge is consumed4 ,the motor thus operating between the pressures of #ejj and #ce lbs4 per square inch1 with a clearance of about #g per cent41 has given an efficiency of #cf per cent4 of the total heat value of kerosene oil4 ,,compression ,,in ,,explosive ,,motors ,that the compression in a gas1 gasoline1 or oil-engine has a direct relation to the power obtained1 has been long known to experienced builders1 having been suggested by ,m4 ,beau de ,rocha1 in #ahfb1 and afterward brought into practical use in the four-cycle or ,otto type about #ahhj4 ,the degree of compression has had a growth from zero1 in the early engines1 to the highest available due to the varying ignition temperatures of the different gases and vapors used for explosive fuel1 in order to avoid premature explosion from the heat of compression4 ,much of the increased power for equal-cylinder capacity is due to compression of the charge from the fact that the most powerful explosion of gases1 or of any form of explosive material1 takes place when the particles are in the closest contact or cohesion with one another1 less energy in this form being consumed by the ingredients themselves to bring about their chemical combination1 and consequently more energy is given out in useful or available work4 ,this is best shown by the ignition of gunpowder1 which1 when ignited in the open air1 burns rapidly1 but without explosion1 an explosion only taking place if the powder be confined or compressed into a small space4 ,illustration3 ,fig4 #ae4--;,diagram of ,heat in the ,gas ,engine ,cylinder4 ,in a gas or gasoline-motor with a small clearance or compression space--with high compression--the surface with which the burning gases come into contact is much smaller in comparison with the compression space in a low-compression motor4 ,another advantage of a high-compression motor is that on account of the smaller clearance of combustion space less cooling water is required than with a low-compression motor1 as the temperature1 and consequently the pressure1 falls more rapidly4 ,the loss of heat through the water-jacket is thus less in the case of a high-compression than in that of a low-compression motor4 ,in the non-compression type of motor the best results were obtained with a charge of #af to #ah parts of gas and #ajj parts of air1 while in the compression type the best results are obtained with an explosive mixture of #g to #aj parts of gas and #ajj parts of air1 thus showing that by the utilization of compression a weaker charge with a greater thermal efficiency is permissible4 ,it has been found that the explosive pressure resulting from the ignition of the charge of gas or gasoline-vapor and air in the gas-engine cylinder is about #d-a_/b times the pressure prior to ignition4 ,the difficulty about getting high compression is that if the pressure is too high the charge is likely to ignite prematurely1 as compression always results in increased temperature4 ,the cylinder may become too hot1 a deposit of carbon1 a projecting electrode or plug body in the cylinder may become incandescent and ignite the charge which has been excessively heated by the high compression and mixture of the hot gases of the previous explosion4 ,,factors ,,limiting ,,compression ,with gasoline-vapor and air the compression should not be raised above about #ij to #ie pounds to the square inch1 many manufacturers not going above #fe or #gj pounds4 ,for natural gas the compression pressure may easily be raised to from #he to #ajj pounds per square inch4 ,for gases of low calorific value1 such as blast-furnace or producer-gas1 the compression may be increased to from #adj to #aij pounds4 ,in fact the ability to raise the compression to a high point with these gases is one of the principal reasons for their successful adoption for gas-engine use4 ,in kerosene injection engines the compression of #bej pounds per square inch has been used with marked economy4 ,many troubles in regard to loss of power and increase of fuel have occurred and will no doubt continue1 owing to the wear of valves1 piston1 and cylinder1 which produces a loss in compression and explosive pressure and a waste of fuel by leakage4 ,faulty adjustment of valve movement is also a cause of loss of power2 which may be from tardy closing of the inlet-valve or a too early opening of the exhaust-valve4 ,the explosive pressure varies to a considerable amount in proportion to the compression pressure by the difference in fuel value and the proportions of air mixtures1 so that for good illuminating gas the explosive pressure may be from #b4e to #d times the compression pressure4 ,for natural gas #c to #d4e1 for gasoline #c to #e1 for producer-gas #b to #c1 and for kerosene by injection #c to #f4 ,the compression temperatures1 although well known and easily computed from a known normal temperature of the explosive mixture1 are subject to the effect of the uncertain temperature of the gases of the previous explosion remaining in the cylinder1 the temperature of its walls1 and the relative volume of the charge1 whether full or scant2 which are terms too variable to make any computations reliable or available4 ,for the theoretical compression temperatures from a known normal temperature1 we append a table of the rise in temperature for the compression pressures in the following table3 ,,table ,,iv4--,,compression ,,temperatures ,,from ,a ,,normal ,,temperature ,,of #fj ,,degrees ,,fahrenheit4 #ajj lbs4 gauge #dhd deg4 #fj lbs4 gauge #cgc deg4 #ij lbs4 gauge #dei deg4 #ej lbs4 gauge #cci deg4 #hj lbs4 gauge #dcc deg4 #dj lbs4 gauge #cja deg4 #gj lbs4 gauge #djd deg4 #cj lbs4 gauge #beh deg4 ---------------------------------------- --------------------- ,,chart ,,for ,,determining ,,compression ,,pressures ,a very useful chart 7,fig4 #af7 for determining compression pressures in gasoline-engine cylinders for various ratios of compression space to total cylinder volume is given by ,p4 ,s4 ,tice1 and described in the ,chilton ,automobile ,directory by the originator as follows3 ,illustration3 ,fig4 #af4--;,chart ,showing ,relation ,between ,compression ,volume and ,pressure4 ,it is many times desirable to have at hand a convenient means for at once determining with accuracy what the compression pressure will be in a gasoline-engine cylinder1 the relationship between the volume of the compression space and the total cylinder volume or that swept by the piston being known4 ,the curve at ,fig4 #af is offered as such a means4 ,it is based on empirical data gathered from upward of two dozen modern automobile engines and represents what may be taken to be the results as found in practice4 ,it is usual for the designer to find compression pressure values1 knowing the volumes from the equation ,p#b ,p#a 7,v#a_/,v#b7a4d #a which is for adiabatic compression of air4 ,equation 7#a7 is right enough in general form but gives results which are entirely too high1 as almost all designers know from experience4 ,the trouble lies in the interchange of heat between the compressed gases and the cylinder walls1 in the diminution of the exponent 7#a4d in the above7 due to the lesser ratio of specific heat of gasoline vapor and in the transfer of heat from the gases which are being compressed to whatever fuel may enter the cylinder in an unvaporized condition4 ,also1 there is always some piston leakage1 and1 if the form of the equation 7#a7 is to be retained1 this also tends to lower the value of the exponent4 ,from experience with many engines1 it appears that compression reaches its highest value in the cylinder for but a short range of motor speeds1 usually during the mid-range4 ,also1 it appears that1 at those speeds at which compression shows its highest values1 the initial pressure at the start of the compression stroke is from 4#e to 4#i lb4 below atmospheric4 ,taking this latter loss value1 which shows more often than those of lesser value1 the compression is seen to start from an initial pressure of #ac4i lbs4 per sq4 in4 absolute4 ,also1 experiment shows that if the exponent be given the value #a4bf1 instead of #a4d1 the equation will embrace all heat losses in the compressed gas1 and compensate for the changed ratio of specific heats for the mixture and also for all piston leakage1 in the average engine with rings in good condition and tight4 ,in the light of the foregoing1 and in view of results obtained from its use1 the above curve is offered--values of ,p#b being found from the equation ,p#b #ac4h 7,v#a_/,v#b7a4bf ,in using this curve it must be remembered that pressures are absolute4 ,thus3 suppose it is desired to know the volumetric relationships of the cylinder for a compression pressure of #ge lbs4 gauge4 ,add atmospheric pressure to the desired gauge pressure #ad4g #ge #hi4g lbs4 absolute4 ,locate this pressure on the scale of ordinates and follow horizontally across to the curve and then vertically downward to the scale of abscissas1 where the ratio of the combustion chamber volume to the total cylinder volume is given1 which latter is equal to the sum of the combustion chamber volume and that of the piston sweep4 ,in the above case it is found that the combustion space for a compression pressure of #ge lbs4 gauge will be 4#bbe of the total cylinder volume1 or 4#bbe _/ 4#gge 4#bije of the piston sweep volume4 ,conversely1 knowing the volumetric ratios1 compression pressure can be read directly by proceeding from the scale of abscissas vertically to the curve and thence horizontally to the scale of ordinates4 ,,causes ,,of ,,heat ,,loss ,,and ,,inefficiency ,,in ,,explosive ,,motors ,the difference realized in the practical operation of an internal combustion heat engine from the computed effect derived from the values of the explosive elements is probably the most serious difficulty that engineers have encountered in their endeavors to arrive at a rational conclusion as to where the losses were located1 and the ways and means of design that would eliminate the causes of loss and raise the efficiency step by step to a reasonable percentage of the total efficiency of a perfect cycle4 ,an authority on the relative condition of the chemical elements under combustion in closed cylinders attributes the variation of temperature shown in the fall of the expansion curve1 and the suppression or retarded evolution of heat1 entirely to the cooling action of the cylinder walls1 and to this nearly all the phenomena hitherto obscure in the cylinder of a gas-engine4 ,others attribute the great difference between the theoretical temperature of combustion and the actual temperature realized in the practical operation of the gas-engine1 a loss of more than one-half of the total heat energy of the combustibles1 partly to the dissociation of the elements of combustion at extremely high temperatures and their reassociation by expansion in the cylinder1 to account for the supposed continued combustion and extra adiabatic curve of the expansion line on the indicator card4 ,illustration3 ,fig4 #ag4--,the ,thompson ,indicator1 an ,instrument for ,determining ,compressions and ,explosion ,pressure ,values and ,recording ,them on ,chart4 ,the loss of heat to the walls of the cylinder1 piston1 and clearance space1 as regards the proportion of wall surface to the volume1 has gradually brought this point to its smallest ratio in the concave piston-head and globular cylinder-head1 with the smallest possible space in the inlet and exhaust passage4 ,the wall surface of a cylindrical clearance space or combustion chamber of one-half its unit diameter in length is equal to #c4adaf square units1 its volume but #j4cibg of a cubic unit2 while the same wall surface in a spherical form has a volume of #j4ebcf of a cubic unit4 ,it will be readily seen that the volume is increased #cc-a_/c per cent4 in a spherical over a cylindrical form for equal wall surfaces at the moment of explosion1 when it is desirable that the greatest amount of heat is generated1 and carrying with it the greatest possible pressure from which the expansion takes place by the movement of the piston4 ,illustration3 ,fig4 #ah4--,spherical ,combustion ,chamber4 ,illustration3 ,fig4 #ai4--;,enlarged ,combustion ,chamber4 ,the spherical form cannot continue during the stroke for mechanical reasons2 therefore some proportion of piston stroke of cylinder volume must be found to correspond with a spherical form of the combustion chamber to produce the least loss of heat through the walls during the combustion and expansion part of the stroke4 ,this idea is illustrated in ,figs4 #ah and #ai1 showing how the relative volumes of cylinder stroke and combustion chamber may be varied to suit the requirements due to the quality of the elements of combustion4 ,although the concave piston-head shows economy in regard to the relation of the clearance volume to the wall area at the moment of explosive combustion1 it may be clearly seen that its concavity increases its surface area and its capacity for absorbing heat1 for which there is no provision for cooling the piston1 save its contact with the walls of the cylinder and the slight air cooling of its back by its reciprocal motion4 ,for this reason the concave piston-head has not been generally adopted and the concave cylinder-head1 as shown in ,fig4 #ai1 with a flat piston-head is the latest and best practice in airplane engine construction4 ,illustration3 ,fig4 #bj4--,mercedes ,aviation ,engine ,cylinder ,section ,showing ,approximately ,spherical ,combustion ,chamber and ,concave ,piston ,top4 ,the practical application of the principle just outlined to one of the most efficient airplane motors ever designed1 the ,mercedes1 is clearly outlined at ,fig4 #bj4 ,,heat ,,losses ,,to ,,cooling ,,water ,the mean temperature of the wall surface of the combustion chamber and cylinder1 as indicated by the temperatures of the circulating water1 has been found to be an important item in the economy of the gas-engine4 ,dugald ,clerk1 in ,england1 a high authority in practical work with the gas-engine1 found that #aj per cent4 of the gas for a stated amount of power was saved by using water at a temperature in which the ejected water from the cylinder-jacket was near the boiling-point1 and ventures the opinion that a still higher temperature for the circulating water may be used as a source of economy4 ,this could be made practical in the case of aviation engines by adjusting the air-cooling surface of the radiator so as to maintain the inlet water at just below the boiling point1 and by the rapid circulation induced by the pump pressure1 to return the water from the cylinder-jacket a few degrees above the boiling point4 ,the thermal displacement systems of cooling employed in automobiles are working under more favorable temperature conditions than those engines in which cooling is more energetic4 ,for a given amount of heat taken from the cylinder by the largest volume of circulating water1 the difference in temperature between inlet and outlet of the water-jacket should be the least possible1 and this condition of the water circulation gives a more even temperature to all parts of the cylinder2 while1 on the contrary1 a cold-water supply1 say at #fj deg4 ,f41 so slow as to allow the ejected water to flow off at a temperature near the boiling-point1 must make a great difference in temperature between the bottom and top of the cylinder1 with a loss in economy in gas and other fuels1 as well as in water1 if it is obtained by measurement4 ,from the foregoing considerations of losses and inefficiencies1 we find that the practice in motor design and construction has not yet reached the desired perfection in its cycular operation4 ,step by step improvements have been made with many changes in design though many have been without merit as an improvement1 farther than to gratify the longings of designers for something different from the other thing1 and to establish a special construction of their own4 ,these efforts may in time produce a motor of normal or standard design for each kind of fuel that will give the highest possible efficiency for all conditions of service4 ,,chapter ,,iv ,engine ,parts and ,functions--,why ,multiple ,cylinder ,engines ,are ,best--,describing ,sequence of ,operations--,simple ,engines--,four and ,six ,cylinder ,vertical ,tandem ,engines--,eight and ,twelve ,cylinder ,v ,engines--,radial ,cylinder ,arrangement--,rotary ,cylinder ,forms4 ,,engine ,,parts ,,and ,,functions ,the principal elements of a gas engine are not difficult to understand and their functions are easily defined4 ,in place of the barrel of the gun one has a smoothly machined cylinder in which a small cylindrical or barrel-shaped element fitting the bore closely may be likened to a bullet or cannon ball4 ,it differs in this important respect1 however1 as while the shot is discharged from the mouth of the cannon the piston member sliding inside of the main cylinder cannot leave it1 as its movements back and forth from the open to the closed end and back again are limited by simple mechanical connection or linkage which comprises crank and connection rod4 ,it is by this means that the reciprocating movement of the piston is transformed into a rotary motion of the crank-shaft4 ,the fly-wheel is a heavy member attached to the crank-shaft of an automobile engine which has energy stored in its rim as the member revolves1 and the momentum of this revolving mass tends to equalize the intermittent pushes on the piston head produced by the explosion of the gas in the cylinder4 ,in aviation engines1 the weight of the propeller or that of rotating cylinders themselves performs the duty of a fly-wheel1 so no separate member is needed4 ,if some explosive is placed in the chamber formed by the piston and closed end of the cylinder and exploded1 the piston would be the only part that would yield to the pressure which would produce a downward movement4 ,as this is forced down the crank-shaft is turned by the connecting rod1 and as this part is hinged at both ends it is free to oscillate as the crank turns1 and thus the piston may slide back and forth while the crank-shaft is rotating or describing a curvilinear path4 ,illustration3 ,fig4 #ba4--,side ,sectional ,view of ,typical ,airplane ,engine1 ,showing ,parts and ,their ,relation to ,each ,other4 ,this ,engine is an ,aeromarine ,design and ,utilizes a ,distinctive ,concentric ,valve ,construction4 ,in addition to the simple elements described it is evident that a gasoline engine must have other parts4 ,the most important of these are the valves1 of which there are generally two to each cylinder4 ,one closes the passage connecting to the gas supply and opens during one stroke of the piston in order to let the explosive gas into the combustion chamber4 ,the other member1 or exhaust valve1 serves as a cover for the opening through which the burned gases can leave the cylinder after their work is done4 ,the spark plug is a simple device which may be compared to the fuse or percussion cap of the cannon4 ,it permits one to produce an electric spark in the cylinder when the piston is at the best point to utilize the pressure which obtains when the compressed gas is fired4 ,the valves are open one at a time1 the inlet valve being lifted from its seat while the cylinder is filling and the exhaust valve is opened when the cylinder is being cleared4 ,they are normally kept seated by means of compression springs4 ,in the simple motor shown at ,fig4 #e1 the exhaust valve is operated by means of a pivoted bell crank rocked by a cam which turns at half the speed of the crank-shaft4 ,the inlet valve operates automatically1 as will be explained in proper sequence4 ,in order to obtain a perfectly tight combustion chamber1 both intake and exhaust valves are closed before the gas is ignited1 because all of the pressure produced by the exploding gas is to be directed against the top of the movable piston4 ,when the piston reaches the bottom of its power stroke1 the exhaust valve is lifted by means of the bell crank which is rocked because of the point or lift on the cam4 ,the cam-shaft is driven by positive gearing and revolves at half the engine speed4 ,the exhaust valve remains open during the whole of the return stroke of the piston1 and as this member moves toward the closed end of the cylinder it forces out burned gases ahead of it1 through the passage controlled by the exhaust valve4 ,the cam-shaft is revolved at half the engine speed because the exhaust valve is raised from its seat during only one stroke out of four1 or only once every two revolutions4 ,obviously1 if the cam was turned at the same speed as the crank-shaft it would remain open once every revolution1 whereas the burned gases are expelled from the individual cylinders only once in two turns of the crank-shaft4 ,,why ,,multiple ,,cylinder ,,forms ,,are ,,best ,owing to the vibration which obtains from the heavy explosion in the large single-cylinder engines used for stationary power other forms were evolved in which the cylinder was smaller and power obtained by running the engine faster1 but these are suitable only for very low powers4 ,when a single-cylinder engine is employed a very heavy fly-wheel is needed to carry the moving parts through idle strokes necessary to obtain a power impulse4 ,for this reason automobile and aircraft designers must use more than one cylinder1 and the tendency is to produce power by frequently occurring light impulses rather than by a smaller number of explosions having greater force4 ,when a single-cylinder motor is employed the construction is heavier than is needed with a multiple-cylinder form4 ,using two or more cylinders conduces to steady power generation and a lessening of vibration4 ,most modern motor cars employ four-cylinder engines because a power impulse may be secured twice every revolution of the crank-shaft1 or a total of four power strokes during two revolutions4 ,the parts are so arranged that while the charge of gas in one cylinder is exploding1 those which come next in firing order are compressing1 discharging the inert gases and drawing in a fresh charge respectively4 ,when the power stroke is completed in one cylinder1 the piston in that member in which a charge of gas has just been compressed has reached the top of its stroke and when the gas is exploded the piston is reciprocated and keeps the crank-shaft turning4 ,when a multiple-cylinder engine is used the fly-wheel can be made much lighter than that of the simpler form and eliminated altogether in some designs4 ,in fact1 many modern multiple-cylinder engines developing #cjj horse-power weigh less than the early single- and double-cylinder forms which developed but one-tenth or one-twentieth that amount of energy4 ,,describing ,,sequence ,,of ,,operations ,referring to ,fig4 #bb1 ,a1 the sequence of operation in a single-cylinder motor can be easily understood4 ,assuming that the crank-shaft is turning in the direction of the arrow1 it will be seen that the intake stroke comes first1 then the compression1 which is followed by the power impulse1 and lastly the exhaust stroke4 ,if two cylinders are used1 it is possible to balance the explosions in such a way that one will occur each revolution4 ,this is true with either one of two forms of four-cycle motors4 ,at ,b1 a two-cylinder vertical engine using a crank-shaft in which the crank-pins are on the same plane is shown4 ,the two pistons move up and down simultaneously4 ,referring to the diagram describing the strokes1 and assuming that the outer circle represents the cycle of operations in one cylinder while the inner circle represents the sequence of events in the other cylinder1 while cylinder ,no4 #a is taking in a fresh charge of gas1 cylinder ,no4 #b is exploding4 ,when cylinder ,no4 #a is compressing1 cylinder ,no4 #b is exhausting4 ,during the time that the charge in cylinder ,no4 #a is exploded1 cylinder ,no4 #b is being filled with fresh gas4 ,while the exhaust gases are being discharged from cylinder ,no4 #a1 cylinder ,no4 #b is compressing the gas previously taken4 ,illustration3 ,fig4 #bb4--;,diagrams ,illustrating ,sequence of ,cycles in ,one- and ,two-,cylinder ,engines ,showing ,more ,uniform ,turning ,effort on ,crank-,shaft with ,two-,cylinder ,motors4 ,the same condition obtains when the crank-pins are arranged at one hundred and eighty degrees and the cylinders are opposed1 as shown at ,c4 ,the reason that the two-cylinder opposed motor is more popular than that having two vertical cylinders is that it is difficult to balance the construction shown at ,b1 so that the vibration will not be excessive4 ,the two-cylinder opposed motor has much less vibration than the other form1 and as the explosions occur evenly and the motor is a simple one to construct1 it has been very popular in the past on light cars and has received limited application on some early1 light airplanes4 ,to demonstrate very clearly the advantages of multiple-cylinder engines the diagrams at ,fig4 #bc have been prepared4 ,at ,a1 a three-cylinder motor1 having crank-pins at one hundred and twenty degrees1 which means that they are spaced at thirds of the circle1 we have a form of construction that gives a more even turning than that possible with a two-cylinder engine4 ,instead of one explosion per revolution of the crank-shaft1 one will obtain three explosions in two revolutions4 ,the manner in which the explosion strokes occur and the manner they overlap strokes in the other cylinder is shown at ,a4 ,assuming that the cylinders fire in the following order1 first ,no4 #a1 then ,no4 #b1 and last ,no4 #c1 we will see that while cylinder ,no4 #a1 represented by the outer circle1 is on the power stroke1 cylinder ,no4 #c has completed the last two-thirds of its exhaust stroke and has started on its intake stroke4 ,cylinder ,no4 #b1 represented by the middle circle1 during this same period has completed its intake stroke and two-thirds of its compression stroke4 ,a study of the diagram will show that there is an appreciable lapse of time between each explosion4 ,three-cylinder engines are not used on aircraft at the present time1 though ,bleriot's flight across the ,british ,channel was made with a three-cylinder ,anzani motor4 ,it was not a conventional form1 however4 ,the three-cylinder engine is practically obsolete at this time for any purpose except penguins or school machines that are incapable of flight and which are used in some ,french training schools for aviators4 ,illustration3 ,fig4 #bc4--;,diagrams ,demonstrating ,clearly ,advantages which ,obtain when ,multiple-,cylinder ,motors are ,used as ,power ,plants4 ,,four- ,,and ,,six-,,cylinder ,,engines ,in the four-cylinder engine operation which is shown at ,fig4 #bc1 ,b1 it will be seen that the power strokes follow each other without loss of time1 and one cylinder begins to fire and the piston moves down just as soon as the member ahead of it has completed its power stroke4 ,in a four-cylinder motor1 the crank-pins are placed at one hundred and eighty degrees1 or on the halves of the crank circle4 ,the crank-pins for cylinders ,no4 #a and ,no4 #d are on the same plane1 while those for cylinders ,no4 #b and ,no4 #c also move in unison4 ,the diagram describing sequence of operations in each cylinder is based on a firing order of one1 two1 four1 three4 ,the outer circle1 as in previous instances1 represents the cycle of operations in cylinder one4 ,the next one toward the center1 cylinder ,no4 #b1 the third circle represents the sequence of events in cylinder ,no4 #c1 while the inner circle outlines the strokes in cylinder four4 ,the various cylinders are working as follows3 #a4 #b4 #c4 #d4 ,explosion ,compression ,exhaust ,intake ,exhaust ,explosion ,intake ,compression ,intake ,exhaust ,compression ,explosion ,compression ,intake ,explosion ,exhaust ,it will be obvious that regardless of the method of construction1 or the number of cylinders employed1 exactly the same number of parts must be used in each cylinder assembly and one can conveniently compare any multiple-cylinder power plant as a series of single-cylinder engines joined one behind the other and so coupled that one will deliver power and produce useful energy at the crank-shaft where the other leaves off4 ,the same fundamental laws governing the action of a single cylinder obtain when a number are employed1 and the sequence of operation is the same in all members1 except that the necessary functions take place at different times4 ,if1 for instance1 all the cylinders of a four-cylinder motor were fired at the same time1 one would obtain the same effect as though a one-piston engine was used1 which had a piston displacement equal to that of the four smaller members4 ,as is the case with a single-cylinder engine1 the motor would be out of correct mechanical balance because all the connecting rods would be placed on crank-pins that lie in the same plane4 ,a very large fly-wheel would be necessary to carry the piston through the idle strokes1 and large balance weights would be fitted to the crank-shaft in an effort to compensate for the weight of the four pistons1 and thus reduce vibratory stresses which obtain when parts are not in correct balance4 ,there would be no advantage gained by using four cylinders in this manner1 and there would be more loss of heat and more power consumed in friction than in a one-piston motor of the same capacity4 ,this is the reason that when four cylinders are used the arrangement of crank-pins is always as shown at ,fig4 #bc1 ,b--i4e41 two pistons are up1 while the other two are at the bottom of the stroke4 ,with this construction1 we have seen that it is possible to string out the explosions so that there will always be one cylinder applying power to the crank-shaft4 ,the explosions are spaced equally4 ,the parts are in correct mechanical balance because two pistons are on the upstroke while the other two are descending4 ,care is taken to have one set of moving members weigh exactly the same as the other4 ,with a four-cylinder engine one has correct balance and continuous application of energy4 ,this insures a smoother running motor which has greater efficiency than the simpler one-1 two-1 and three-cylinder forms previously described4 ,eliminating the stresses which would obtain if we had an unbalanced mechanism and irregular power application makes for longer life4 ,obviously a large number of relatively light explosions will produce less wear and strain than would a lesser number of powerful ones4 ,as the parts can be built lighter if the explosions are not heavy1 the engine can be operated at higher rotative speeds than when large and cumbersome members are utilized4 ,four-cylinder engines intended for aviation work have been built according to the designs shown at ,fig4 #bd1 but these forms are unconventional and seldom if ever used4 ,illustration3 ,fig4 #bd4--,showing ,three ,possible ,though ,unconventional ,arrangements of ,four-,cylinder ,engines4 ,the six-cylinder type of motor1 the action of which is shown at ,fig4 #bc1 ,c1 is superior to the four-cylinder1 inasmuch as the power strokes overlap1 and instead of having two explosions each revolution we have three explosions4 ,the conventional crank-shaft arrangement in a six-cylinder engine is just the same as though one used two three-cylinder shafts fastened together1 so pistons #a and #f are on the same plane as are pistons #b and #e4 ,pistons #c and #d also travel together4 ,with the cranks arranged as outlined at ,fig4 #bc1 ,c1 the firing order is one1 five1 three1 six1 two1 four4 ,the manner in which the power strokes overlap is clearly shown in the diagram4 ,an interesting comparison is also made in the diagrams at ,fig4 #be and in the upper corner of ,fig4 #bc1 ,c4 ,illustration3 ,fig4 #be4--;,diagrams ,outlining ,advantages of ,multiple ,cylinder ,motors1 and ,why ,they ,deliver ,power ,more ,evenly ,than ,single ,cylinder ,types4 ,a rectangle is divided into four columns2 each of these corresponds to one hundred and eighty degrees1 or half a revolution4 ,thus the first revolution of the crank-shaft is represented by the first two columns1 while the second revolution is represented by the last two4 ,taking the portion of the diagram which shows the power impulse in a one-cylinder engine1 we see that during the first revolution there has been no power impulse4 ,during the first half of the second revolution1 however1 an explosion takes place and a power impulse is obtained4 ,the last portion of the second revolution is devoted to exhausting the burned gases1 so that there are three idle strokes and but one power stroke4 ,the effect when two cylinders are employed is shown immediately below4 ,illustration3 ,fig4 #bf4--;,diagrams ,showing ,duration of ,events for a ,four-,stroke ,cycle1 ,six-,cylinder ,engine4 ,here we have one explosion during the first half of the first revolution in one cylinder and another during the first half of the second revolution in the other cylinder4 ,with a four-cylinder engine there is an explosion each half revolution1 while in a six-cylinder engine there is one and one-half explosions during each half revolution4 ,when six cylinders are used there is no lapse of time between power impulses1 as these overlap and a continuous and smooth-turning movement is imparted to the crank shaft4 ,the diagram shown at ,fig4 #bf1 prepared by ,e4 ,p4 ,pulley1 can be studied to advantage in securing an idea of the coordination of effort that takes place in an engine of the six-cylinder type4 ,,actual ,,duration ,,of ,,different ,,strokes ,illustration3 ,fig4 #bg4--;,diagram ,showing ,actual ,duration of ,different ,strokes in ,degrees4 ,in the diagrams previously presented the writer has assumed1 for the sake of simplicity1 that each stroke takes place during half of one revolution of the crank-shaft1 which corresponds to a crank-pin travel of one hundred and eighty degrees4 ,the actual duration of these strokes is somewhat different4 ,for example1 the inlet stroke is usually a trifle more than a half revolution1 and the exhaust is always considerably more4 ,the diagram showing the comparative duration of the strokes is shown at ,fig4 #bg4 ,the inlet valve opens ten degrees after the piston starts to go down and remains open thirty degrees after the piston has reached the bottom of its stroke4 ,this means that the suction stroke corresponds to a crank-pin travel of two hundred degrees1 while the compression stroke is measured by a movement of but one hundred and fifty degrees4 ,it is common practice to open the exhaust valve before the piston reaches the end of the power stroke so that the actual duration of the power stroke is about one hundred and forty degrees1 while the exhaust stroke corresponds to a crank-pin travel of two hundred and twenty-five degrees4 ,in this diagram1 which represents proper time for the valves to open and close1 the dimensions in inches given are measured on the fly-wheel and apply only to a certain automobile motor4 ,if the fly-wheel were smaller ten degrees would take up less than the dimensions given1 while if the fly-wheel was larger a greater space on its circumference would represent the same crank-pin travel4 ,aviation engines are timed by using a timing disc attached to the crank-shaft as they are not provided with fly-wheels4 ,obviously1 the distance measured in inches will depend upon the diameter of the disc1 though the number of degrees interval would not change4 ,illustration3 ,fig4 #bh4--;,another ,diagram to ,facilitate ,understanding ,sequence of ,functions in ,six-,cylinder ,engine4 ,,eight- ,,and ,,twelve-,,cylinder ,v ,,engines ,those who have followed the development of the gasoline engine will recall the arguments that were made when the six-cylinder motor was introduced at a time that the four-cylinder type was considered standard4 ,the arrival of the eight-cylinder has created similar futile discussion of its practicability as this is so clearly established as to be accepted without question4 ,it has been a standard power plant for aeroplanes for many years1 early exponents having been the ,antoinette1 the ,woolsley1 the ,renault1 the ,e4 ,n4 ,v4 in ,europe and the ,curtiss in the ,united ,states4 ,illustration3 ,fig4 #bi4--,types of ,eight-,cylinder ,engines ,showing the ,advantage of the ,v ,method of ,cylinder ,placing4 ,the reason the ,v type shown at ,fig4 #bi1 ,a is favored is that the all-in-line form which is shown at ,fig4 #bi1 ,b is not practical for aircraft because of its length4 ,compared to the standard four-cylinder engine it is nearly twice as long and it required a much stronger and longer crank-shaft4 ,it will be evident that it could not be located to advantage in the airplane fuselage4 ,these undesirable factors are eliminated in the ,v type eight-cylinder motor1 as it consists of two blocks of four cylinders each1 so arranged that one set or block is at an angle of forty-five degrees from the vertical center line of the motor1 or at an angle of ninety degrees with the other set4 ,this arrangement of cylinders produces a motor that is no longer than a four-cylinder engine of half the power would be4 ,illustration3 ,fig4 #cj4--;,curves ,showing ,torque of ,various ,engine ,types ,demonstrate ,graphically ,marked ,advantage of the ,eight-,cylinder ,type4 ,apparently there is considerable misconception as to the advantage of the two extra cylinders of the eight as compared with the six-cylinder4 ,it should be borne in mind that the multiplication in the number of cylinders noticed since the early days of automobile development has not been for solely increasing the power of the engine1 but to secure a more even turning movement1 greater flexibility and to eliminate destructive vibration4 ,the ideal internal combustion motor1 is the one having the most uniform turning movement with the least mechanical friction loss4 ,study of the torque outlines or plotted graphics shown at ,figs4 #be and #cj will show how multiplication of cylinders will produce steady power delivery due to overlapping impulses4 ,the most practical form would be that which more nearly conforms to the steady running produced by a steam turbine or electric motor4 ,the advocates of the eight-cylinder engine bring up the item of uniform torque as one of the most important advantages of the eight-cylinder design4 ,a number of torque diagrams are shown at ,fig4 #cj4 ,while these appear to be deeply technical1 they may be very easily followed when their purpose is explained4 ,at the top is shown the torque diagram of a single-cylinder motor of the four-cycle type4 ,the high point in the line represents the period of greatest torque or power generation1 and it will be evident that this occurs early in the first revolution of the crank-shaft4 ,below this diagram is shown a similar curve except that it is produced by a four-cylinder engine4 ,inspection will show that the turning-moment is much more uniform than in the single cylinder2 similarly1 the six-cylinder diagram is an improvement over the four1 and the eight-cylinder diagram is an improvement over the six-cylinder4 ,illustration3 ,fig4 #ca4--;,diagrams ,showing ,how ,increasing ,number of ,cylinders ,makes for ,more ,uniform ,power ,application4 ,the reason that practically continuous torque is obtained in an eight-cylinder engine is that one cylinder fires every ninety degrees of crank-shaft rotation1 and as each impulse lasts nearly seventy-five per cent4 of the stroke1 one can easily appreciate that an engine that will give four explosions per revolution of the crank-shaft will run more uniformly than one that gives but three explosions per revolution1 as the six-cylinder does1 and will be twice as smooth running as a four-cylinder1 in which but two explosions occur per revolution of the crank-shaft4 ,the comparison is so clearly shown in graphical diagrams and in ,fig4 #ca that further description is unnecessary4 ,any eight-cylinder engine may be considered a twin-four1 twelve-cylinder engines may be considered twin sixes4 ,illustration3 ,fig4 #cb4--;,how the ,angle ,between the ,cylinders of an ,eight- and ,twelve-,cylinder ,v ,motor ,varies4 ,the only points in which an eight-cylinder motor differs from a four-cylinder is in the arrangement of the connecting rod1 as in many designs it is necessary to have two rods working from the same crank-pin4 ,this difficulty is easily overcome in some designs by staggering the cylinders and having the two connecting rod big ends of conventional form side by side on a common crank-pin4 ,in other designs one rod is a forked form and works on the outside of a rod of the regular pattern4 ,still another method is to have a boss just above the main bearing on one connecting rod to which the lower portion of the connecting rod in the opposite cylinder is hinged4 ,as the eight-cylinder engine may actually be made lighter than the six-cylinder of equal power1 it is possible to use smaller reciprocating parts1 such as pistons1 connecting rods and valve gear1 and obtain higher engine speed with practically no vibration4 ,the firing order in nearly every case is the same as in a four-cylinder except that the explosions occur alternately in each set of cylinders4 ,the firing order of an eight-cylinder motor is apt to be confusing to the motorist1 especially if one considers that there are eight possible sequences4 ,the majority of engineers favor the alternate firing from side to side4 ,firing orders will be considered in proper sequence4 ,illustration3 ,fig4 #cc4--,the ,hall-,scott ,four-,cylinder #ajj ,horse-,power ,aviation ,motor4 ,illustration3 ,fig4 #cd4--,two ,views of the ,duesenberg ,sixteen ,valve ,four-,cylinder ,aviation ,motor4 ,the demand of aircraft designers for more power has stimulated designers to work out twelve-cylinder motors4 ,these are high-speed motors incorporating all recent features of design in securing light reciprocating parts1 large valve openings1 etc4 ,the twelve-cylinder motor incorporates the best features of high-speed motor design and there is no need at this time to discuss further the pros and cons of the twelve-cylinder versus the eight or six1 because it is conceded by all that there is the same degree of steady power application in the twelve over the eight as there would be in the eight over the six4 ,the question resolves itself into having a motor of high power that will run with minimum vibration and that produces smooth action4 ,this is well shown by diagrams at ,fig4 #ca4 ,it should be remembered that if an eight-cylinder engine will give four explosions per revolution of the fly-wheel1 a twelve-cylinder type will give six explosions per revolution1 and instead of the impulses coming #ij degrees crank travel apart1 as in the case of the eight-cylinder1 these will come but #fj degrees of crank travel apart in the case of the twelve-cylinder4 ,for this reason1 the cylinders of a twelve are usually separated by #fj degrees while the eight has the blocks spaced #ij degrees apart4 ,the comparison can be easily made by comparing the sectional views of ,vee engines at ,fig4 #cb4 ,when one realizes that the actual duration of the power stroke is considerably greater than #abj degrees crank travel1 it will be apparent that the overlapping of explosions must deliver a very uniform application of power4 ,vee engines have been devised having the cylinders spaced but #de degrees apart1 but the explosions cannot be timed at equal intervals as when #ij degrees separate the cylinder center lines4 ,illustration3 ,fig4 #ce4--,the ,hall-,scott ,six-,cylinder ,aviation ,engine4 ,,radial ,,cylinder ,,arrangements ,illustration3 ,fig4 #cf4--,the ,curtiss ,eight-,cylinder1 #bjj ,horse-,power ,aviation ,engine4 ,while the fixed cylinder forms of engines1 having the cylinders in tandem in the four- and six-cylinder models as shown at ,figs4 #cc to #ce inclusive and the eight-cylinder ,v types as outlined at ,figs4 #cf and #cg have been generally used and are most in favor at the present time1 other forms of motors having unconventional cylinder arrangements have been devised1 though most of these are practically obsolete4 ,while many methods of decreasing weight and increasing mechanical efficiency of a motor are known to designers1 one of the first to be applied to the construction of aeronautical power plants was an endeavor to group the components1 which in themselves were not extremely light1 into a form that would be considerably lighter than the conventional design4 ,as an example1 we may consider those multiple-cylinder forms in which the cylinders are disposed around a short crank-case1 either radiating from a common center as at ,fig4 #ch or of the fan shape shown at ,fig4 #ci4 ,this makes it possible to use a crank-case but slightly larger than that needed for one or two cylinders and it also permits of a corresponding decrease in length of the crank-shaft4 ,the weight of the engine is lessened because of the reduction in crank-shaft and crank-case weight and the elimination of a number of intermediate bearings and their supporting webs which would be necessary with the usual tandem construction4 ,while there are six power impulses to every two revolutions of the crank-shaft1 in the six-cylinder engine1 they are not evenly spaced as is possible with the conventional arrangement4 ,illustration3 ,fig4 #cg4--,the ,sturtevant ,eight-,cylinder1 ,high ,speed ,aviation ,motor4 ,illustration3 ,fig4 #ch4--;,anzani #dj-ej ,horse-,power ,five-,cylinder ,air ,cooled ,engine4 ,in the ,anzani form1 which is shown at ,fig4 #ch1 the crank-case is stationary and a revolving crank-shaft is employed as in conventional construction4 ,the cylinders are five in number and the engine develops #dj to #ej ,h4,p4 with a weight of #gb kilograms or #aeh4d lbs4 ,the cylinders are of the usual air-cooled form having cooling flanges only part of the way down the cylinder4 ,by using five cylinders it is possible to have the power impulses come regularly1 they coming #ade deg4 crank-shaft travel apart1 the crank-shaft making two turns to every five explosions4 ,the balance is good and power output regular4 ,the valves are placed directly in the cylinder head and are operated by a common pushrod4 ,attention is directed to the novel method of installing the carburetor which supplies the mixture to the engine base from which inlet pipes radiate to the various cylinders4 ,this engine is used on ,french school machines4 ,illustration3 ,fig4 #ci4--,unconventional ,six-,cylinder ,aircraft ,motor of ,masson ,design4 ,in the form shown at ,fig4 #ci six cylinders are used1 all being placed above the crank-shaft center line4 ,this engine is also of the air-cooled form and develops #ej ,h4 ,p4 and weighs #aje kilograms1 or #bca lbs4 ,the carburetor is connected to a manifold casting attached to the engine base from which the induction pipes radiate to the various cylinders4 ,the propeller design and size relative to the engine is clearly shown in this view4 ,while flights have been made with both of the engines described1 this method of construction is not generally followed and has been almost entirely displaced abroad by the revolving motors or by the more conventional eight-cylinder ,v engines4 ,both of the engines shown were designed about eight years ago and would be entirely too small and weak for use in modern airplanes intended for active duty4 ,,rotary ,,engines ,illustration3 ,fig4 #dj4--,the ,gnome ,fourteen-,cylinder ,revolving ,motor4 ,rotary engines such as shown at ,fig4 #dj are generally associated with the idea of light construction and it is rather an interesting point that is often overlooked in connection with the application of this idea to flight motors1 that the reason why rotary engines are popularly supposed to be lighter than the others is because they form their own fly-wheel1 yet on aeroplanes1 engines are seldom fitted with a fly-wheel at all4 ,as a matter of fact the ,gnome engine is not so light because it is a rotary motor1 and it is a rotary motor because the design that has been adopted as that most conducive to lightness is also most suited to an engine working in this way4 ,the cylinders could be fixed and crank-shaft revolve without increasing the weight to any extent4 ,there are two prime factors governing the lightness of an engine1 one being the initial design1 and the other the quality of the materials employed4 ,the consideration of reducing weight by cutting away metal is a subsidiary method that ought not to play a part in standard practice1 however useful it may be in special cases4 ,in the ,gnome rotary engine the lightness is entirely due to the initial design and to the materials employed in manufacture4 ,thus1 in the first case1 the engine is a radial engine1 and has its seven or nine cylinders spaced equally around a crank-chamber that is no wider or rather longer than would be required for any one of the cylinders4 ,this shortening of the crank-chamber not only effects a considerable saving of weight on its own account1 but there is a corresponding saving in the shafts and other members1 the dimensions of which are governed by the size of the crank-chamber4 ,with regard to materials1 nothing but steel is used throughout1 and most of the metal is forged chrome nickel steel4 ,the beautifully steady running of the engine is largely due to the fact that there are literally no reciprocating parts in the absolute sense1 the apparent reciprocation between the pistons and cylinders being solely a relative reciprocation since both travel in circular paths1 that of the pistons1 however1 being electric by one-half of the stroke length to that of the cylinder4 ,while the ,gnome engine has many advantages1 on the other hand the head resistance offered by a motor of this type is considerable2 there is a large waste of lubricating oil due to the centrifugal force which tends to throw the oil away from the cylinders2 the gyroscopic effect of the rotary motor is detrimental to the best working of the aeroplane1 and moreover it requires about seven per cent4 of the total power developed by the motor to drive the revolving cylinders around the shaft4 ,of necessity1 the compression of this type of motor is rather low1 and an additional disadvantage manifests itself in the fact that there is as yet no satisfactory way of muffling the rotary type of motor4 ,the modern ,gnome engine has been widely copied in various ,european countries1 but its design was originated in ,america1 the early ,adams-,farwell engine being the pioneer form4 ,it has been made in seven- and nine-cylinder types and forms of double these numbers4 ,the engine illustrated at ,fig4 #dj is a fourteen-cylinder form4 ,the simple engines have an odd number of cylinders in order to secure evenly spaced explosions4 ,in the seven-cylinder1 the impulses come #ajb4h deg4 apart4 ,in the nine-cylinder form1 the power strokes are spaced #hj deg4 apart4 ,the fourteen-cylinder engine is virtually two seven-cylinder types mounted together1 the cranks being just the same as in a double cylinder opposed motor1 the explosions coming #ea4d deg4 apart2 while in the eighteen-cylinder model the power impulses come every #dj deg4 cylinder travel4 ,other rotary motors have been devised1 such as the ,le ,rhone and the ,clerget in ,france and several ,german copies of these various types4 ,the mechanical features of these motors will be fully considered later4 ,,chapter ,v ,properties of ,liquid ,fuels--,distillates of ,crude ,petroleum-- ,principles of ,carburetion ,outlined--,air ,needed to ,burn ,gasoline --,what a ,carburetor ,should ,do--,liquid ,fuel ,storage and ,supply-- ,vacuum ,fuel ,feed--,early ,vaporizer ,forms--,development of ,float ,feed ,carburetor--,maybach's ,early ,design--,concentric ,float and ,jet ,type--,schebler ,carburetor--,claudel ,carburetor--,stewart ,metering ,pin ,type--,multiple ,nozzle ,vaporizers--,two-,stage ,carburetor--,master ,multiple ,jet ,type--,compound ,nozzle ,zenith ,carburetor--,utility of ,gasoline ,strainers--,intake ,manifold ,design and ,construction--,compensating for ,various ,atmospheric ,conditions--,how ,high ,altitude ,affects ,power--,the ,diesel ,system-- ,notes on ,carburetor ,installation--,notes on ,carburetor ,adjustment4 ,there is no appliance that has more material value upon the efficiency of the internal combustion motor than the carburetor or vaporizer which supplies the explosive gas to the cylinders4 ,it is only in recent years that engineers have realized the importance of using carburetors that are efficient and that are so strongly and simply made that there will be little liability of derangement4 ,as the power obtained from the gas-engine depends upon the combustion of fuel in the cylinders1 it is evident that if the gas supplied does not have the proper proportions of elements to insure rapid combustion the efficiency of the engine will be low4 ,when a gas engine is used as a stationary installation it is possible to use ordinary illuminating or natural gas for fuel1 but when this prime mover is applied to automobiles or airplanes it is evident that considerable difficulty would be experienced in carrying enough compressed coal gas to supply the engine for even a very short trip4 ,fortunately1 the development of the internal-combustion motor was not delayed by the lack of suitable fuel4 ,engineers were familiar with the properties of certain liquids which gave off vapors that could be mixed with air to form an explosive gas which burned very well in the engine cylinders4 ,a very small quantity of such liquids would suffice for a very satisfactory period of operation4 ,the problem to be solved before these liquids could be applied in a practical manner was to evolve suitable apparatus for vaporizing them without waste4 ,among the liquids that can be combined with air and burned1 gasoline is the most volatile and is the fuel utilized by internal-combustion engines4 ,the widely increasing scope of usefulness of the internal-combustion motor has made it imperative that other fuels be applied in some instances because the supply of gasoline may in time become inadequate to supply the demand4 ,in fact1 abroad this fuel sells for fifty to two hundred per cent4 more than it does in ,america because most of the gasoline used must be imported from this country or ,russia4 ,because of this foreign engineers have experimented widely with other substances1 such as alcohol1 benzol1 and kerosene1 but more to determine if they can be used to advantage in motor cars than in airplane engines4 ,,distillates ,,of ,,crude ,,petroleum ,crude petroleum is found in small quantities in almost all parts of the world1 but a large portion of that produced commercially is derived from ,american wells4 ,the petroleum obtained in this country yields more of the volatile products than those of foreign production1 and for that reason the demand for it is greater4 ,the oil fields of this country are found in ,pennsylvania1 ,indiana1 and ,ohio1 and the crude petroleum is usually in association with natural gas4 ,this mineral oil is an agent from which many compounds and products are derived1 and the products will vary from heavy sludges1 such as asphalt1 to the lighter and more volatile components1 some of which will evaporate very easily at ordinary temperatures4 ,the compounds derived from crude petroleum are composed principally of hydrogen and carbon and are termed ,hydrocarbons4 ,in the crude product one finds many impurities1 such as free carbon1 sulphur1 and various earthy elements4 ,before the oil can be utilized it must be subjected to a process of purifying which is known as refining1 and it is during this process1 which is one of destructive distillation1 that the various liquids are separated4 ,the oil was formerly broken up into three main groups of products as follows3 ,highly volatile1 naphtha1 benzine1 gasoline1 eight to ten per cent4 ,light oils1 such as kerosene and light lubricating oils seventy to eighty per cent4 ,heavy oils or residuum five to nine per cent4 ,from the foregoing it will be seen that the available supply of gasoline is determined largely by the demand existing for the light oils forming the larger part of the products derived from crude petroleum4 ,new processes have been recently discovered by which the lighter oils1 such as kerosene1 are reduced in proportion and that of gasoline increased1 though the resulting liquid is neither the high grade1 volatile gasoline known in the early days of motoring nor the low grade kerosene4 ,,principles ,,of ,,carburetion ,,outlined ,the process of carburetion is combining the volatile vapors which evaporate from the hydrocarbon liquids with certain proportions of air to form an inflammable gas4 ,the quantities of air needed vary with different liquids and some mixtures burn quicker than do other combinations of air and vapor4 ,combustion is simply burning and it may be rapid1 moderate or slow4 ,mixtures of gasoline and air burn quickly1 in fact the combustion is so rapid that it is almost instantaneous and we obtain what is commonly termed an explosion4 ,therefore the explosion of gas in the automobile engine cylinder which produces the power is really a combination of chemical elements which produce heat and an increase in the volume of the gas because of the increase in temperature4 ,if the gasoline mixture is not properly proportioned the rate of burning will vary1 and if the mixture is either too rich or too weak the power of the explosion is reduced and the amount of power applied to the piston is decreased proportionately4 ,in determining the proper proportions of gasoline and air1 one must take the chemical composition of gasoline into account4 ,the ordinary liquid used for fuel is said to contain about eight-four per cent4 carbon and sixteen per cent4 hydrogen4 ,air is composed of oxygen and nitrogen and the former has a great affinity1 or combining power1 with the two constituents of hydrocarbon liquids4 ,therefore1 what we call an explosion is merely an indication that oxygen in the air has combined with the carbon and hydrogen of the gasoline4 ,,air ,,needed ,,to ,,burn ,,gasoline ,in figuring the proper volume of air to mix with a given quantity of fuel1 one takes into account the fact that one pound of hydrogen requires eight pounds of oxygen to burn it1 and one pound of carbon needs two and one-third pounds of oxygen to insure its combustion4 ,air is composed of one part of oxygen to three and one-half portions of nitrogen by weight4 ,therefore for each pound of oxygen one needs to burn hydrogen or carbon four and one-half pounds of air must be allowed4 ,to insure combustion of one pound of gasoline which is composed of hydrogen and carbon we must furnish about ten pounds of air to burn the carbon and about six pounds of air to insure combustion of hydrogen1 the other component of gasoline4 ,this means that to burn one pound of gasoline one must provide about sixteen pounds of air4 ,while one does not usually consider air as having much weight1 at a temperature of sixty-two degrees ,fahrenheit about fourteen cubic feet of air will weigh a pound1 and to burn a pound of gasoline one would require about two hundred cubic feet of air4 ,this amount will provide for combustion theoretically1 but it is common practice to allow twice this amount because the element nitrogen1 which is the main constituent of air1 is an inert gas and instead of aiding combustion it acts as a deterrent of burning4 ,in order to be explosive1 gasoline vapor must be combined with definite quantities of air4 ,mixtures that are rich in gasoline ignite quicker than those which have more air1 but these are only suitable when starting or when running slowly1 as a rich mixture ignites much quicker than a weak mixture4 ,the richer mixture of gasoline and air not only burns quicker but produces the most heat and the most effective pressure in pounds per square inch of piston top area4 ,the amount of compression of the charge before ignition also has material bearing on the force of the explosion4 ,the higher the degree of compression the greater the force exerted by the rapid combustion of the gas4 ,it may be stated that as a general thing the maximum explosive pressure is somewhat more than four times the compression pressure prior to ignition4 ,a charge compressed to sixty pounds will have a maximum of approximately two hundred and forty pounds2 compacted to eighty pounds it will produce a pressure of about three hundred pounds on each square inch of piston area at the beginning of the power stroke4 ,mixtures varying from one part of gasoline vapor to four of air to others having one part of gasoline vapor to thirteen of air can be ignited1 but the best results are obtained when the proportions are one to five or one to seven1 as this mixture is said to be the one that will produce the highest temperature1 the quickest explosion1 and the most pressure4 ,,what ,a ,,carburetor ,,should ,,do ,while it is apparent that the chief function of a carbureting device is to mix hydrocarbon vapors with air to secure mixtures that will burn1 there are a number of factors which must be considered before describing the principles of vaporizing devices4 ,almost any device which permits a current of air to pass over or through a volatile liquid will produce a gas which will explode when compressed and ignited in the motor cylinder4 ,modern carburetors are not only called upon to supply certain quantities of gas1 but these must deliver a mixture to the cylinders that is accurately proportioned and which will be of proper composition at all engine speeds4 ,illustration3 ,fig4 #da4--;,how ,gravity ,feed ,fuel ,tank ,may ,be ,mounted ,back of ,engine and ,secure ,short ,fuel ,line4 ,flexible control of the engine is sought by varying the engine speed by regulating the supply of gas to the cylinders4 ,the power plant should run from its lowest to its highest speed without any irregularity in torque1 i4e41 the acceleration should be gradual rather than spasmodic4 ,as the degree of compression will vary in value with the amount of throttle opening1 the conditions necessary to obtain maximum power differ with varying engine speeds4 ,when the throttle is barely opened the engine speed is low and the gas must be richer in fuel than when the throttle is wide open and the engine speed high4 ,when an engine is turning over slowly the compression has low value and the conditions are not so favorable to rapid combustion as when the compression is high4 ,at high engine speeds the gas velocity through the intake piping is higher than at low speeds1 and regular engine action is not so apt to be disturbed by condensation of liquid fuel in the manifold due to excessively rich mixture or a superabundance of liquid in the stream of carbureted air4 ,,liquid ,,fuel ,,storage ,,and ,,supply ,the problem of gasoline storage and method of supplying the carburetor is one that is determined solely by design of the airplane4 ,while the object of designers should be to supply the fuel to the carburetor by as simple means as possible the fuel supply system of some airplanes is quite complex4 ,the first point to consider is the location of the gasoline tank4 ,this depends upon the amount of fuel needed and the space available in the fuselage4 ,a very simple and compact fuel supply system is shown at ,fig4 #da4 ,in this instance the fuel container is placed immediately back of the engine cylinder4 ,the carburetor which is carried as indicated is joined to the tank by a short piece of copper or flexible rubber tubing4 ,this is the simplest possible form of fuel supply system and one used on a number of excellent airplanes4 ,as the sizes of engines increase and the power plant fuel consumption augments it is necessary to use more fuel1 and to obtain a satisfactory flying radius without frequent landings for filling the fuel tank it is necessary to supply large containers4 ,when a very powerful power plant is fitted1 as on battle planes of high capacity1 it is necessary to carry large quantities of gasoline4 ,in order to use a tank of sufficiently large capacity it may be necessary to carry it lower than the carburetor4 ,when installed in this manner it is necessary to force fuel out of the tank by air pressure or to pump it with a vacuum tank because the gasoline tank is lower than the carburetor it supplies and the gasoline cannot flow by gravity as in the simpler systems4 ,while the pressure and gravity feed systems are generally used in airplanes1 it may be well to describe the vacuum lift system which has been widely applied to motor cars and which may have some use in connection with airplanes as these machines are developed4 ,,stewart ,,vacuum ,,fuel ,,feed ,one of the marked tendencies has been the adoption of a vacuum fuel feed system to draw the gasoline from tanks placed lower than the carburetor instead of using either exhaust gas or air pressure to achieve this end4 ,the device generally fitted is the ,stewart vacuum feed tank which is clearly shown in section at ,fig4 #db4 ,in this system the suction of a motor is employed to draw gasoline from the main fuel tank to the auxiliary tank incorporated in the device and from this tank the liquid flows to the carburetor4 ,it is claimed that all the advantages of the pressure system are obtained with very little more complication than is found on the ordinary gravity feed4 ,the mechanism is all contained in the cylindrical tank shown1 which may be mounted either on the front of the dash or on the side of the engine as shown4 ,illustration3 ,fig4 #db4--,the ,stewart ,vacuum ,fuel ,feed ,tank4 ,the tank is divided into two chambers1 the upper one being the filling chamber and the lower one the emptying chamber4 ,the former1 which is at the top of the device1 contains the float valve1 as well as the pipes running to the main fuel container and to the intake manifold4 ,the lower chamber is used to supply the carburetor with gasoline and is under atmospheric pressure at all times1 so the flow of fuel from it is by means of gravity only4 ,since this chamber is located somewhat above the carburetor1 there must always be free flow of fuel4 ,atmospheric pressure is maintained by the pipes ,a and ,b1 the latter opening into the air4 ,in order that the fuel will be sucked from a main tank to the upper chamber1 the suction valve must be opened and the atmospheric valve closed4 ,under these conditions the float is at the bottom and the suction at the intake manifold produces a vacuum in the tank which draws the gasoline from the main tank to the upper chamber4 ,when the upper chamber is filled at the proper height the float rises to the top1 this closing the suction valve and opening the atmospheric valve4 ,as the suction is now cut off1 the lower chamber is filled by gravity owing to there being atmospheric pressure in both upper and lower chambers4 ,a flap valve is provided between the two chambers to prevent the gasoline in the lower one from being sucked back into the upper one4 ,the atmospheric and suction valves are controlled by the levers ,c and ,d1 both of which are pivoted at ,e1 their outer ends being connected by two coil springs4 ,it is seen that the arrangement of these two springs is such that the float must be held at the extremity of its movement1 and that it cannot assume an intermediate position4 ,this intermittent action is required to insure that the upper part of the tank may be under atmospheric pressure part of the time for the gasoline to flow to the lower chamber4 ,when the level of gasoline drops to a certain point1 the float falls1 thus opening the suction valve and closing the atmospheric valve4 ,the suction of the motor then causes a flow of fuel from the main container4 ,as soon as the level rises to the proper height the float returns to its upper position4 ,it takes about two seconds for the chamber to become full enough to raise the float1 as but 4#je gallon is transferred at a time4 ,the pipe running from the bottom of the lower chamber to the carburetor extends up a ways1 so that there is but little chance of dirt or water being carried to the float chamber4 ,if the engine is allowed to stand long enough so that the tank becomes empty1 it will be replenished after the motor has been cranked over four or five times with the throttle closed4 ,the installation of the ,stewart ,vacuum-,gravity ,system is very simple4 ,the suction pipe is tapped into the manifold at a point as near the cylinders as possible1 while the fuel pipe is inserted into the gasoline tank and runs to the bottom of that member4 ,there is a screen at the end of the fuel pipe to prevent any trouble due to deposits of sediment in the main container4 ,as the fuel is sucked from the gasoline tank a small vent must be made in the tank filler cap so that the pressure in the main tank will always be that of the atmosphere4 ,,early ,,vaporizer ,,forms ,the early types of carbureting devices were very crude and cumbersome1 and the mixture of gasoline vapor and air was accomplished in three ways4 ,the air stream was passed over the surface of the liquid itself1 through loosely placed absorbent material saturated with liquid1 or directly through the fuel4 ,the first type is known as the surface carburetor and is now practically obsolete4 ,the second form is called the wick carburetor because the air stream was passed over or through saturated wicking4 ,the third form was known as a bubbling carburetor4 ,while these primitive forms gave fairly good results with the early slow-speed engines and the high grade1 or very volatile1 gasoline which was first used for fuel1 they would be entirely unsuitable for present forms of engines because they would not carburate the lower grades of gasoline which are used to-day1 and would not supply the modern high-speed engines with gas of the proper consistency fast enough even if they did not have to use very volatile gasoline4 ,the form of carburetor used at the present time operates on a different principle4 ,these devices are known as spraying carburetors4 ,the fuel is reduced to a spray by the suction effect of the entering air stream drawing it through a fine opening4 ,the advantage of this construction is that a more thorough amalgamation of the gasoline and air particles is obtained4 ,with the earlier types previously considered the air would combine with only the more volatile elements1 leaving the heavier constituents in the tank4 ,as the fuel became stale it was difficult to vaporize it1 and it had to be drained off and fresh fuel provided before the proper mixture would be produced4 ,it will be evident that when the fuel is sprayed into the air stream1 all the fuel will be used up and the heavier portions of the gasoline will be taken into the cylinder and vaporized just as well as the more volatile vapors4 ,illustration3 ,fig4 #dc4--,marine-,type ,mixing ,valve1 by which ,gasoline is ,sprayed into ,air ,stream ,through ,small ,opening in ,air-,valve ,seat4 ,the simplest form of spray carburetor is that shown at ,fig4 #dc4 ,in this the gasoline opening through which the fuel is sprayed into the entering air stream is closed by the spring-controlled mushroom valve which regulates the main air opening as well4 ,when the engine draws in a charge of air it unseats the valve and at the same time the air flowing around it is saturated with gasoline particles through the gasoline opening4 ,the mixture thus formed goes to the engine through the mixture passage4 ,two methods of varying the fuel proportions are provided4 ,one of these consists of a needle valve to regulate the amount of gasoline1 the other is a knurled screw which controls the amount of air by limiting the lift of the jump valve4 ,,development ,,of ,,float-,,feed ,,carburetor ,the modern form of spraying carburetor is provided with two chambers1 one a mixing chamber through which the air stream passes and mixes with a gasoline spray1 the other a float chamber in which a constant level of fuel is maintained by simple mechanism4 ,a jet or standpipe is used in the mixing chamber to spray the fuel through and the object of the float is to maintain the fuel level to such a point that it will not overflow the jet when the motor is not drawing in a charge of gas4 ,with the simple forms of generator valve in which the gasoline opening is controlled by the air valve1 a leak anywhere in either valve or valve seat will allow the gasoline to flow continuously whether the engine is drawing in a charge or not4 ,the liquid fuel collects around the air opening1 and when the engine inspires a charge it is saturated with gasoline globules and is excessively rich4 ,with a float-feed construction1 which maintains a constant level of gasoline at the right height in the standpipe1 liquid fuel will only be supplied when drawn out of the jet by the suction effect of the entering air stream4 ,,maybach',s ,,early ,,design ,the first form of spraying carburetor ever applied successfully was evolved by ,maybach for use on one of the earliest ,daimler engines4 ,the general principles of operation of this pioneer float-feed carburetor are shown at ,fig4 #dd1 ,a4 ,the mixing chamber and valve chamber were one and the standpipe or jet protruded into the mixing chamber4 ,it was connected to the float compartment by a pipe4 ,the fuel from the tank entered the top of the float compartment and the opening was closed by a needle valve carried on top of a hollow metal float4 ,when the level of gasoline in the float chamber was lowered the float would fall and the needle valve uncover the opening4 ,this would permit the gasoline from the tank to flow into the float chamber1 and as the chamber filled the float would rise until the proper level had been reached1 under which conditions the float would shut off the gasoline opening4 ,on every suction stroke of the engine the inlet valve1 which was an automatic type1 would leave its seat and a stream of air would be drawn through the air opening and around the standpipe or jet4 ,this would cause the gasoline to spray out of the tube and mix with the entering air stream4 ,illustration3 ,fig4 #dd4--,tracing ,evolution of ,modern ,spray ,carburetor4 ,a--,early ,form ,evolved by ,maybach4 ,b4--,phoenix-,daimler ,modification of ,maybach's ,principle4 ,c--,modern ,concentric ,float ,automatic ,compensating ,carburetor4 ,the form shown at ,b was a modification of ,maybach's simple device and was first used on the ,phoenix-,daimler engines4 ,several improvements are noted in this device4 ,first1 the carburetor was made one unit by casting the float and mixing chambers together instead of making them separate and joining them by a pipe1 as shown at ,a4 ,the float construction was improved and the gasoline shut-off valve was operated through leverage instead of being directly fastened to the float4 ,the spray nozzle was surrounded by a choke tube which concentrated the air stream around it and made for more rapid air flow at low engine speeds4 ,a conical piece was placed over the jet to break up the entering spray into a mist and insure more intimate admixture of air and gasoline4 ,the air opening was provided with an air cone which had a shutter controlling the opening so that the amount of air entering could be regulated and thus vary the mixture proportions within certain limits4 ,,concentric ,,float ,,and ,,jet ,,type ,the form shown at ,b has been further improved1 and the type shown at ,c is representative of modern single jet practice4 ,in this the float chamber and mixing chamber are concentric4 ,a balanced float mechanism which insures steadiness of feed is used1 the gasoline jet or standpipe is provided with a needle valve to vary the amount of gasoline supplied the mixture and two air openings are provided4 ,the main air port is at the bottom of the vaporizer1 while an auxiliary air inlet is provided at the side of the mixing chamber4 ,there are two methods of controlling the mixture proportions in this form of carburetor4 ,one may regulate the gasoline needle or adjust the auxiliary air valve4 ,,schebler ,,carburetor ,a ,schebler carburetor1 which has been used on some airplane engines1 is shown in ,fig4 #de4 ,it will be noticed that a metering pin or needle valve opens the jet when the air valve opens4 ,the long arm of a leverage is connected to the air valve1 while the short arm is connected to the needle1 the reduction in leverage being such that the needle valve is made to travel much less than the air valve4 ,for setting the amount of fuel passed or the size of the jet orifice when running with the air valve closed1 there is a screw which raises or lowers the fulcrum of the lever and there is also a dash control having the same effect by pushing down the fulcrum against a small spring4 ,a long extension is given to the venturi tube which is very narrow around the jet orifices1 which are horizontal and shown at ,a in the drawing4 ,fuel enters the float chamber through the union ,m1 and the spring ,p holds the metering pin upward against the restraining action of the lever4 ,the air valve may be set by an easily adjustable knurled screw shown in the drawing1 and fluttering of the valve is prevented by the piston dash pot carried in a chamber above the valve into which the valve stem projects4 ,the primary air enters beneath the jet passage and there is a small throttle in the intake to increase the speed of air flow for starting purposes4 ,the carburetor is adapted for the use of a hot-air connection to the stove around the exhaust pipe and it is recommended that such a fitting be supplied4 ,the lever which controls the supply of air through the primary air intake is so arranged that if desired it can be connected with a linkage on the dash or control column by means of a flexible wire4 ,illustration3 ,fig4 #de4--,new ,model of ,schebler ,carburetor ,with ,metering ,valve and ,extended ,venturi4 ,note ,mechanical ,connection ,between ,air ,valve and ,fuel ,regulating ,needle4 ,,the ,,claudel 7,,french7 ,,carburetor ,illustration3 ,fig4 #df4--,the ,claudel ,carburetor4 ,this carburetor is of extremely simple construction1 because it has no supplementary or auxiliary air valve and no moving parts except the throttle controlling the gas flow4 ,the construction is already shown in ,fig4 #df4 ,the spray jet is eccentric with a surrounding sleeve or tube in which there are two series of small orifices1 one at the top and the other near the bottom4 ,the former are about level with the spray jet opening4 ,the sleeve surrounding the nozzle is closed at the top4 ,the air1 passing the upper holes in the sleeve1 produces a vacuum in the sleeve1 thereby drawing air in through the bottom holes4 ,it is this moving interior column of air that controls the flow of gasoline from the nozzle4 ,owing to the friction of the small passages1 the speed of air flow through the sleeve does not increase as fast as the speed of air flow outside the sleeve1 hence there is a tendency for the mixture to remain constant4 ,the throttle of this carburetor is of the barrel type1 and the top of the spray nozzle and its surrounding sleeve are located inside the throttle4 ,,stewart ,,metering ,,pin ,,carburetor ,the carburetor shown at ,fig4 #dg is a metering type in which the vacuum at the jet is controlled by the weight of the metering valve surrounding the upright metering pin4 ,the only moving part is the metering valve1 which rises and falls with the changes in vacuum4 ,the air chamber surrounds the metering valve1 and there is a mixing chamber above4 ,as the valve is drawn up the gasoline passage is enlarged on account of the predetermined taper on the metering pin1 and the air passage also is increased proportionately1 giving the correct mixture4 ,a dashpot at the bottom of the valve checks flutter4 ,in idling the valve rests on its seat1 practically closing the air and giving the necessary idling mixture4 ,a passage through the valve acts as an aspirating tube4 ,when the valve is closed altogether the primary air passes through ducts in the valve itself1 giving the proper amount for idling4 ,the one adjustment consists in raising or lowering the tapered metering pin1 increasing or decreasing the supply of gasoline4 ,dash control is supplied4 ,this pulls down the metering pin1 increasing the gasoline flow4 ,the duplex type for eight- and twelve-cylinder motors is the same in principle as model #be1 but it is a double carburetor synchronized as to throttle movements1 adjustments1 etc4 ,the duplex for aeronautical motors is made of cast aluminum alloy4 ,illustration3 ,fig4 #dg4--,the ,stewart ,metering ,pin ,carburetor4 ,,multiple ,,nozzle ,,vaporizers ,to secure properly proportioned mixtures some carburetor designers have evolved forms in which two or more nozzles are used in a common mixing chamber4 ,the usual construction is to use two1 one having a small opening and placed in a small air tube and used only for low speeds1 the other being placed in a larger air tube and having a slightly augmented bore so that it is employed on intermediate speeds4 ,at high speeds both jets would be used in series4 ,some multiple jet carburetors could be considered as a series of these instruments1 each one being designed for certain conditions of engine action4 ,they would vary from small size just sufficient to run the engine at low speed to others having sufficient capacity to furnish gas for the highest possible engine speed when used in conjunction with the smaller members which have been brought into service progressively as the engine speed has been augmented4 ,the multiple nozzle carburetor differs from that in which a single spray tube is used only in the construction of the mixing chamber1 as a common float bowl can be used to supply all spray pipes4 ,it is common practice to bring the jets into action progressively by some form of mechanical connection with the throttle or by automatic valves4 ,the object of any multiple nozzle carburetor is to secure greater flexibility and endeavor to supply mixtures of proper proportions at all speeds of the engine4 ,it should be stated1 however1 that while devices of this nature lend themselves readily to practical application it is more difficult to adjust them than the simpler forms having but one nozzle4 ,when a number of jets are used the liability of clogging up the carburetor is increased1 and if one or more of the nozzles is choked by a particle of dirt or water the resulting mixture trouble is difficult to detect4 ,one of the nozzles may supply enough gasoline to permit the engine to run well at certain speeds and yet not be adequate to supply the proper amount of gas under other conditions4 ,in adjusting a multiple jet carburetor in which the jets are provided with gasoline regulating needles1 it is customary to consider each nozzle as a distinct carburetor and to regulate it to secure the best motor action at that throttle position which corresponds to the conditions under which the jet is brought into service4 ,for instance1 that supplied the primary mixing chamber should be regulated with the throttle partly closed1 while the auxiliary jet should be adjusted with the throttle fully opened4 ,,ball ,,and ,,ball ,,two-,,stage ,,carburetor ,illustration3 ,fig4 #dh4--,the ,ball and ,ball ,two-,stage ,carburetor4 ,this is a two-stage vaporizing device1 hot air being used in the primary or initial stage of vaporization and cold air in the supplementary stage4 ,referring to the sectional illustration at ,fig4 #dh1 it will be seen that there is a hot-air passage with a choke-valve2 the primary venturi appears at ,b2 ,j is its gasoline jet1 and ,v is a spring-loaded idling valve in a fixed air opening4 ,these parts constitute the primary system4 ,in the secondary system ,a is a cold-air passage1 ,t a butterfly valve and ,j a gasoline jet discharging into the cold-air passage4 ,this system is brought into operation by opening the butterfly ,t4 ,a connection between the butterfly ,t and the throttle1 not shown1 throws the butterfly wide open when the throttle is not quite wide open2 at all other times the butterfly is held closed by a spring4 ,the cylindrical chamber at the right of the mixing chamber has an extension ,e of reduced diameter connecting it with the intake manifold through a passage ,d4 ,a restricted opening connects the float chamber with the cylindrical chamber so that the gasoline level is the same in both4 ,a loosely fitting plunger ,p in the cylindrical chamber has an upward extension into the small part of the chamber4 ,o is a small air opening and ,m is a passage from the cylindrical chamber to the mixing chamber4 ,air constantly passes through this when the carburetor is in operation4 ,the carburetor is really two in one4 ,the primary carburetor is made up of a central jet in a venturi passage4 ,the float chamber is eccentric4 ,in the air passage there is a fixed opening1 and additional air is taken in by the opening through suction of a spring-opposed air valve4 ,the second stage1 which comes into play as soon as the carburetor is called upon for additional mixture above low medium speeds1 is made up of an independent air passage containing another air valve4 ,as the valve is opened this jet is uncovered1 and air is led past it4 ,for easy starting an extra passage leads from the float bowl passage to a point above the throttle4 ,all the suction falls upon this passage when the throttle is closed4 ,the passage contains a plunger and acts as a pick-up device4 ,when the vacuum increases the plunger rises and shuts off the flow of gasoline from the intake passage4 ,as the throttle is opened the vacuum in the intake passage is broken1 and the plunger falls1 causing gasoline to gather above it4 ,this is immediately drawn through the pick-up passage and gives the desired mixture for acceleration4 ,,master ,,multiple-,,jet ,,carburetor ,illustration3 ,fig4 #di4--,the ,master ,carburetor4 ,this carburetor1 shown in detail in ,figs4 #di and #ej1 has been very popular in racing cars and aviation engines because of exceptionally good pick-up qualities and its thorough atomization of fuel4 ,its principle of operation is the breaking up of the fuel by a series of jets1 which vary in number from fourteen to twenty-one1 according to the size of the carburetor4 ,these are uncovered by opening the throttle1 which is curved--a patented feature--to secure the correct progression of jets4 ,the carburetor has an eccentric float chamber1 from which the gasoline is led to the jet piece from which the jets stand up in a row4 ,the tops of these jets are closed until the throttle is opened far enough to pass them1 which it does progressively4 ,the air opening is at the bottom1 and the throttle opening is such that a modified venturi is formed4 ,the throttle is carried in a cylindrical barrel with the jets placed below it1 and the passage from the barrel to the intake is arranged so that there is no interruption in the flow4 ,for easy starting a dash-controlled shutter closes off the air1 throwing the suction on the jets1 thus giving a rich mixture4 ,illustration3 ,fig4 #ej4--,sectional ,view of ,master ,carburetor ,showing ,parts4 ,the only adjustment is for idling1 and once that is fixed it need never be touched4 ,this is in the form of a screw and regulates the position of the throttle when at idling position4 ,the dash control has high-speed1 normal and rich-starting positions4 ,in installing the ,master carburetor the float chamber may be turned either toward the radiator or driver's seat4 ,if the float is turned toward the radiator1 however1 a forward lug plate should be ordered2 otherwise it will be difficult to install the control4 ,the throttle lever must go all the way to the stop lug or maximum power will not be secured4 ,in adjusting the idle screw it is turned in for rich and out for lean4 ,,compound ,,nozzle ,,zenith ,,carburetor ,illustration3 ,fig4 #ea4--,sectional ,view of ,zenith ,compound ,nozzle ,compensating ,carburetor4 ,the ,zenith carburetor1 shown at ,fig4 #ea1 has become very popular for airplane engine use because of its simplicity1 as mixture compensation is secured by a compensating compound nozzle principle that works very well in practice4 ,to illustrate this principle briefly1 let us consider the elementary type of carburetor or mixing valve1 as shown in ,fig4 #eb1 ,a4 ,it consists of a single jet or spraying nozzle placed in the path of the incoming air and fed from the usual float chamber4 ,it is a natural inference to suppose that as the speed of the motor increases1 both the flow of air and of gasoline will increase in the same proportion4 ,unhappily1 such is not the case4 ,there is a law of liquid bodies which states that the flow of gasoline from the jet increases under suction faster than the flow of air1 giving a mixture which grows richer and richer--a mixture containing a much higher percentage of gasoline at high suction than at low4 ,the tendency is shown by the accompanying curve 7,fig4 #eb1 ,b71 which gives the ratio of gasoline to air at varying speeds from this type of jet4 ,the mixture is practically constant only between narrow limits and at very high speed4 ,the most common method of correcting this defect is by putting various auxiliary air valves which1 adding air1 tends to dilute this mixture as it gets too rich4 ,it is difficult with makeshift devices to gauge this dilution accurately for every motor speed4 ,illustration3 ,fig4 #eb4--;,diagrams ,explaining ,action of ,baverey ,compound ,nozzle ,used in ,zenith ,carburetor4 ,now1 if we have a jet which grows richer as the suction increases1 the opposite type of jet is one which would grow leaner under similar conditions4 ,baverey1 the inventor of the ,zenith1 discovered the principle of the constant flow device which is shown in ,fig4 #eb1 ,c4 ,here a certain fixed amount of gasoline determined by the opening ,i is permitted to flow by gravity into the well ,j open to the air4 ,the suction at jet ,h has no effect upon the gravity compensator ,i because the suction is destroyed by the open well ,j4 ,the compensator1 then1 delivers a steady rate of flow per unit of time1 and as the motor suction increases more air is drawn up1 while the amount of gasoline remains the same and the mixture grows poorer and poorer4 ,fig4 #eb1 ,d1 shows this curve4 ,by combining these two types of rich and poor mixture carburetors the ,zenith compound nozzle was evolved4 ,in ,fig4 #eb1 ,e1 we have both the direct suction or richer type leading through pipe ,e and nozzle ,g and the constant flow device of ,baverey shown at ,j1 ,i1 ,k and nozzle ,h4 ,one counteracts the defects of the other1 so that from the cranking of the motor to its highest speed there is a constant ratio of air and gasoline to supply efficient combustion4 ,in addition to the compound nozzle the ,zenith is equipped with a starting and idling well1 shown in the cut of ,model ,l carburetor at ,p and ,j4 ,this terminates in a priming hole at the edge of the butterfly valve1 where the suction is greatest when this valve is slightly open4 ,the gasoline is drawn up by the suction at the priming hole and1 mixed with the air rushing by the butterfly1 gives an ideal slow speed mixture4 ,at higher speeds with the butterfly valve opened further the priming well ceases to operate and the compound nozzle drains the well and compensates correctly for any motor speed4 ,illustration3 ,fig4 #ec4--,the ,zenith ,duplex ,carburetor for ,airplane ,motors of the ,v ,type4 ,with the coming of the double motor containing eight or twelve cylinders arranged in two ,v blocks1 the question of good carburetion has been a problem requiring much study4 ,the single carburetor has given only indifferent results due to the strong cross suction in the inlet manifold from one set of cylinders to the other4 ,this naturally led to the adoption of two carburetors in which each set of cylinders was independently fed by a separate carburetor4 ,results from this system were very good when the two carburetors were working exactly in unison1 but as it was extremely difficult to accomplish this co-operation1 especially where the adjustable type was employed1 this system never gained in favor4 ,the next logical step was the ,zenith ,duplex1 shown at ,fig4 #ec4 ,this consists of two separate and distinct carburetors joined together so that a common gasoline float chamber and air inlet could be used by both4 ,it does away with cross suction in the manifold because each set of cylinders has a separate intake of its own4 ,it does away with two carburetors and makes for simplicity4 ,the practical application of the ,zenith carburetor to the ,curtiss #ij horse-power ,,ox-#b motor used on the ,,jn-#d standard training machine is shown at ,fig4 #ed1 which outlines a rear view of the engine in question4 ,the carburetor is carried low to permit of fuel supply from a gravity tank carried back of the motor4 ,illustration3 ,fig4 #ed4--,rear ,view of ,curtiss ,,ox-#b #ij ,horse-,power ,airplane ,motor ,showing ,carburetor ,location and ,hot ,air ,leads4 ,,utility ,,of ,,gasoline ,,strainers ,many carburetors include a filtering screen at the point where the liquid enters the float chamber in order to keep dirt or any other foreign matter which may be present in the fuel from entering the float chamber4 ,this is not general practice1 however1 and the majority of vaporizers do not include a filter in their construction4 ,it is very desirable that the dirt should be kept out of the carburetor because it may get under the float control fuel valve and cause flooding by keeping it raised from its seat4 ,if it finds its way into the spray nozzle it may block the opening so that no gasoline will issue or may so constrict the passage that only very small quantities of fuel will be supplied the mixture4 ,where the carburetor itself is not provided with a filtering screen a simple filter is usually installed in the pipe line between the gasoline tank and the float chamber4 ,some simple forms of filters and separators are shown at ,fig4 #ee4 ,that at ,a consists of a simple brass casting having a readily detachable gauze screen and a settling chamber of sufficient capacity to allow the foreign matter to settle to the bottom1 from which it is drained out by a pet cock4 ,any water or dirt in the gasoline will settle to the bottom of the chamber1 and as all fuel delivered to the carburetor must pass through the wire gauze screen it is not likely to contain impurities when it reaches the float chamber4 ,the heavier particles1 such as scale from the tank or dirt and even water1 all of which have greater weight than the gasoline1 will sink to the bottom of the chamber1 whereas light particles1 such as lint1 will be prevented from flowing into the carburetor by the filtering screen4 ,illustration3 ,fig4 #ee4--,types of ,strainers ,interposed ,between ,vaporizer and ,gasoline ,tank to ,prevent ,water or ,dirt ,passing ,into ,carbureting ,device4 ,the filtering device shown at ,b is a larger appliance than that shown at ,a1 and should be more efficient as a separator because the gasoline is forced to pass through three filtering screens before it reaches the carburetor4 ,the gasoline enters the device shown at ,c through a bent pipe which leads directly to the settling chamber and from thence through a wire gauze screen to the upper compartment which leads to the carburetor4 ,the device shown at ,d is a combination strainer1 drain1 and sediment cup4 ,the filtering screen is held in place by a spring and both are removed by taking out a plug at the bottom of the device4 ,the shut-off valve at the top of the device is interposed between the sediment cup and the carburetor4 ,this separating device is incorporated with the gasoline tank and forms an integral part of the gasoline supply system4 ,the other types shown are designed to be interposed between the gasoline tank and the carburetor at any point in the pipe line where they may be conveniently placed4 ,,intake ,,manifold ,,design ,,and ,,construction ,on four- and six-cylinder engines and in fact on all multiple-cylinder forms1 it is important that the piping leading from the carburetor to the cylinders be made in such a way that the various cylinders will receive their full quota of gas and that each cylinder will receive its charge at about the same point in the cycle of operations4 ,in order to make the passages direct the bends should be as few as possible1 and when curves are necessary they should be of large radius because an abrupt corner will not only impede gas flow but will tend to promote condensation of the fuel4 ,every precaution should be taken with four- and six-cylinder engines to insure equitable gas distribution to the valve chambers if regular action of the power plant is desired4 ,if the gas pipe has many turns and angles it will be difficult to charge all cylinders properly4 ,on some six-cylinder aviation engines1 two carburetors are used because of trouble experienced with manifolds designed for one carburetor4 ,duplex carburetors are necessary to secure the best results from eight- and twelve-cylinder ,v engines4 ,the problem of intake piping is simplified to some extent on block motors where the intake passage is cored in the cylinder casting and where but one short pipe is needed to join this passage to the carburetor4 ,if the cylinders are cast in pairs a simple pipe of ,t or ,y form can be used with success4 ,when the engine is of a type using individual cylinder castings1 especially in the six-cylinder power plants1 the proper application and installation of suitable piping is a difficult problem4 ,the reader is referred to the various engine designs outlined to ascertain how the inlet piping has been arranged on representative aviation engines4 ,intake piping is constructed in two ways1 the most common method being to cast the manifold of brass or aluminum4 ,the other method1 which is more costly1 is to use a built-up construction of copper or brass tubing with cast metal elbows and ,y pieces4 ,one of the disadvantages advanced against the cast manifold is that blowholes may exist which produce imperfect castings and which will cause mixture troubles because the entering gas from the carburetor1 which may be of proper proportions1 is diluted by the excess air which leaks in through the porous casting4 ,another factor of some moment is that the roughness of the walls has a certain amount of friction which tends to reduce the velocity of the gases1 and when projecting pieces are present1 such as core wire or other points of metal1 these tend to collect the drops of liquid fuel and thus promote condensation4 ,the advantage of the built-up construction is that the walls of the tubing are very smooth1 and as the castings are small it is not difficult to clean them out thoroughly before they are incorporated in the manifold4 ,the tubing and castings are joined together by hard soldering1 brazing or autogenous welding4 ,,compensating ,,for ,,varying ,,atmospheric ,,conditions ,the low-grade gasoline used at the present time makes it necessary to use vaporizers that are more susceptible to atmospheric variations than when higher grade and more volatile liquids are vaporized4 ,sudden temperature changes1 sometimes being as much as forty degrees rise or fall in twelve hours1 affect the mixture proportions to some extent1 and not only changes in temperature but variations in altitude also have a bearing on mixture proportions by affecting both gasoline and air4 ,as the temperature falls the specific gravity of the gasoline increases and it becomes heavier1 this producing difficulty in vaporizing4 ,the tendency of very cold air is to condense gasoline instead of vaporizing it and therefore it is necessary to supply heated air to some carburetors to obtain proper mixtures during cold weather4 ,in order that the gas mixtures will ignite properly the fuel must be vaporized and thoroughly mixed with the entering air either by heat or high velocity of the gases4 ,the application of air stoves to the ,curtiss ,,ox-#b motor is clearly shown at ,fig4 #ed4 ,it will be seen that flexible metal pipes are used to convey the heated air to the air intakes of the duplex mixing chamber4 ,illustration3 ,fig4 #ef4--;,chart ,showing ,diminution of ,air ,pressure as ,altitude ,increases4 ,,how ,,high ,,altitude ,,affects ,,power ,any internal combustion engine will show less power at high altitudes than it will deliver at sea level1 and this has caused a great deal of questioning4 ,there is a good reason for this1 says a writer in ,motor ,age1 and it is a physical impossibility for the engine to do otherwise4 ,the difference is due to the lower atmospheric pressure the higher up we get4 ,that is1 at sea level the atmosphere has a pressure of #ad4g pounds per square inch2 at #e1jjj feet above sea level the pressure is approximately #ab4ac pounds per square inch1 and at #aj1jjj feet it is #aj pounds per square inch4 ,from this it will be seen that the final pressure attained after the piston has driven the gas into compressed condition ready for firing is lower as the atmospheric pressure drops4 ,this means that there is not so much power in the compressed charge of gas the higher up you get above sea level4 ,for example1 suppose the compression ratio to be #d-a_/b to #a2 in other words1 suppose the air space above the piston to have #d-a_/b times the volume when the piston is at the bottom of its stroke that it has when the piston is at the top of the stroke4 ,that is a common compression ratio for an average motor1 and is chosen because it is considered to be the best for maximum horse-power and in order that the compression pressure will not be so high as to cause pre-ignition4 ,knowing the compression ratio1 we can determine the final pressure immediately before ignition by substituting in the standard formula3 ,p#a ,p7,v_/,v#a7a4c in which ,p is the atmospheric pressure2 ,p#a is the final pressure1 and ,v_/,v#a is the compression ratio1 therefore ,p#a #ad4g 7#d4e7a4c #ajd pounds per square inch1 absolute4 ,that is1 #ajd pounds per square inch is the most efficient final compression pressure to have for this engine at sea level1 since it comes directly from the compression ratio4 ,now supposing we consider that the altitude is #g1jjj feet above sea level4 ,at this height the atmospheric pressure is #aa4be pounds per square inch1 approximately4 ,in this case we can again substitute in the formula1 using the new atmospheric pressure figure4 ,the equation becomes3 ,p#a #aa4be 7#d4e7a4c--gi4d pounds per square inch1 absolute4 ,therefore we now have a final compression pressure of only #gi4d pounds per square inch1 which is considerably below the pressure we have just found to be the most efficient for the motor4 ,the resulting power drop is evident4 ,it should be borne in mind that these final compression pressures are absolute pressures--that is1 they include the atmospheric pressure4 ,in the first case1 to get the pressure above atmospheric you would subtract #ad4g and in the latter #aa4be would have to be deducted4 ,in other words1 where the sea level compression is #hi4c pounds per square inch above the atmosphere1 the same motor will have only a compression pressure of #fh4ae pounds per square inch above the atmosphere at #g1jjj feet elevation4 ,from the above it is evident that in order to bring the final compression pressure up to the efficient figure we have determined1 a different compression ratio would have to be used4 ,that is1 the final volume would have to be less1 and as it is impossible to vary this to meet the conditions of altitude1 the loss of power cannot be helped except by the replacing of the standard pistons with some that are longer above the wrist-pin so as to reduce the space above the pistons when on top center4 ,then if the ratio is thereby raised to some such figures as #e to #a1 the engine will again have its proper final pressure1 but it will still not have as much power as it would have at sea level1 since the horse-power varies directly with the atmospheric pressure1 final compression being kept constant4 ,that is1 at #g1jjj feet the horse-power of an engine that had #dj horse-power at sea level would be equal to #aa4be ------- #cj4f horse-power4 #ad4g ,if the original compression ratio of #d4e were retained1 the drop in horse-power would be even greater than this4 ,these computations and remarks will make it clear that the designer who contemplates building an airplane for high altitude use should see to it that it is of sufficient power to compensate for the drop that is inevitable when it is up in the air4 ,this is often illustrated in stationary gas-engine installations4 ,an engine that had a sea-level rating amply sufficient for the work required1 might not be powerful enough when brought up several thousand feet4 ,when one considers that airplanes attain heights of over #ah1jjj feet1 it will be evident that an ample margin of engine power is necessary4 ,,the ,,diesel ,,system ,a system of fuel supply developed by the late ,dr4 ,diesel1 a ,german chemist and engineer1 is attracting considerable attention at the present time on account of the ability of the ,diesel engine to burn low-grade fuels1 such as crude petroleum4 ,in this system the engines are built so that very high compressions are used1 and only pure air is taken into the cylinder on the induction stroke4 ,this is compressed to a pressure of about #ejj pounds per square inch1 and sufficient heat is produced by this compression to explode a hydrocarbon mixture4 ,as the air which is compressed to this high point cannot burn1 the fuel is introduced into the cylinder combustion chamber under still higher compression than that of the compressed air1 and as it is injected in a fine stream it is immediately vaporized because of the heat4 ,just as soon as the compressed air becomes thoroughly saturated with the liquid fuel1 it will explode on account of the degree of heat present in the combustion chamber4 ,such motors have been used in marine and stationary applications1 but are not practical for airplanes or motor cars because of lack of flexibility and great weight in proportion to power developed4 ,the ,diesel engine is the standard power plant used in submarine boats and motor ships1 as its efficiency renders it particularly well adapted for large units4 ,,notes ,,on ,,carburetor ,,installation ,,in ,,airplanes ,a writer in ,the ,aeroplane1 an ,english publication1 discourses on some features of carburetor installation that may be of interest to the aviation student1 so portions of the dissertation are reproduced herewith4 ,users of airplanes fitted with ordinary type carburetors will do well to note carefully the way in which these are fitted1 for several costly machines have been burnt lately through the sheer carelessness of their users4 ,these particular machines were fitted with a high powered ,v-type engine1 made by a firm which is famous as manufacturers of automobiles de luxe4 ,in these engines there are four carburetors1 mounted in the ,v between the cylinders4 ,when the engine is fitted as a tractor1 the float chambers are in front of the jet chambers4 ,consequently1 when the tail of the machine is resting on the ground1 the jets are lower than the level of the gasoline in the float chamber4 ,quite naturally1 the gasoline runs out of the jet1 if it is left turned on when the machine is standing in its normal position1 and trickles into the ,v at the top of the crank-case4 ,thence it runs down to the tail of the engine1 where the magnetos are fitted1 and saturates them4 ,if left long enough1 the gasoline manages to soak well into the fuselage before evaporating4 ,and what does evaporate makes an inflammable gas in the forward cockpit4 ,then some one comes along and starts up the engine4 ,the spark-gap of the magneto gives one flash1 and the whole front of the machine proceeds to give a ,fourth of ,july performance forthwith4 ,naturally1 one safeguard is to turn the petrol off directly the machine lands4 ,another is never to turn it on till the engine is actually being started up4 ,one would be asking too much of the human boy--who is officially regarded as the only person fit to fly an aeroplane--if one depended upon his memory of such a detail to save his machine1 though one might perhaps reasonably expect the older pilots to remember not to forget4 ,even so1 other means of prevention are preferable1 for fire is quite as likely to occur from just the same cause if the engine happens to be a trifle obstinate in starting1 and so gives the carburetors several minutes in which to drip--in which operation they would probably be assisted by air-mechanics 'tickling' them4 ,one way out of the trouble is to fit drip tins under the jet chamber to catch the gasoline as it falls4 ,this is all very well just to prevent fire while the machine is being started up1 but it will not save it if it is left standing with the tail on the ground and the petrol turned on1 for the drip tins will then fill up and run over4 ,and if it catches then1 the contents of the drip tins merely add fuel to the fire4 ,reversing ,carburetors ,yet another way is to turn the carburetors round1 so that the float chambers are behind the jets1 and so come below them when the tail is on the ground1 thus cutting off the gasoline low down in the jets4 ,there seems to be no particular mechanical difficulty about this1 though ,i must confess that ,i did not note very carefully whether the reversal of the float chambers would make them foul any other fittings on the engine4 ,it has been argued1 however1 that doing this would starve the engine of gasoline when climbing at a steep angle1 as the gasoline would then be lowered in the jets and need more suction to get into the cylinders4 ,this is rather a pretty point of amateur motor mechanics to discuss1 for1 obviously1 when the same engine is used as a 'pusher' instead of a tractor1 the jets are in front of the floats1 and there seems to be no falling off in power4 ,starvation of ,mixture ,moreover1 the higher a machine goes the lower is the atmospheric pressure1 and1 consequently1 the less is the amount of air sucked in at each induction stroke4 ,this means1 of course1 that with the gasoline supply the mixture at high altitudes is too rich1 so that1 in order to get precisely the right mixture when very high up1 it is necessary to reduce the gasoline supply by screwing down the needle valve between the tank and the carburetor--at least1 that has been the experience of various high-flying pilots4 ,no doubt something might be done in the way of forced air feed to compensate for reduced atmospheric pressure1 but it remains to be proved whether the extra weight of mechanism involved would pay for the extra power obtained4 ,variable compression might do something1 also1 to even things up1 but here1 also1 weight of mechanism has to be considered4 ,in any case1 at present1 the higher one goes the more the power of the engine is reduced1 for less air means a less volume of mixture per cylinder1 and as the petrol feed has to be starved to suit the smaller amount of air available1 this means further loss of power4 ,i do not know whether anyone has evolved a carburetor which automatically starves the gasoline feed when high up1 but it seems possible that when an airplane is sagging about 'up against the ceiling'--as a ,french pilot described the absolute limit of climb for his particular machine--it might be a good thing to have the jets in front of the float chamber1 for then a certain amount of automatic starvation would take place4 ,when a machine is right up at its limiting height1 and the pilot is doing his best to make it go higher still1 it is probably flying with its tail as low as the pilot dares to let it go1 and the lateral and longitudinal controls are on the verge of vanishing1 so that if the carburetor jets are behind the float chambers there is bound to be an over-rich mixture in any case4 ,there is even a possibility of a careless or ignorant pilot carrying on in this tail-down position till one set of cylinders cuts out altogether1 in which case the carburetor feeding that set may flood over1 just as if the machine were on the ground1 and the whole thing may catch fire4 ,whereas1 with the jets in front of the floats1 though the mixture may starve a trifle1 there is1 at any rate1 no danger of fire through climbing with the tail down4 ,a ,diving ,danger ,on the other hand1 in a 'pusher' with this type of engine1 if the jets are in their normal position--which is in front of the floats--there is danger of fire in a dive4 ,that is to say1 if the pilot throttles right down1 or switches off and relies on air pressure on his propeller to start the engine again1 so that the gasoline is flooding over out of the jets instead of being sucked into the engine1 there may be flooding over the magnetos if the dive is very steep and prolonged4 ,in any case1 a long dive will mean a certain amount of flooding1 and1 probably1 a good deal of choking and spitting by the engine before it gets rid of the over-rich mixture and picks up steady firing again4 ,which may indicate to young pilots that it is not good to come down too low under such circumstances1 trusting entirely to their engines to pick up at once and get going before they hit the ground4 ,on the whole1 it seems that it might be better practice to set the carburetors thwartwise of engines1 for then jets and floats would always be at approximately the same level1 no matter what the longitudinal position of the machine1 and it is never long enough in one position at a big lateral angle to raise any serious carburetor troubles4 ,car manufacturers who dive cheerfully into the troubled waters of aero-engine designs are a trifle apt to forget that their engines are put into positions on airplanes which would be positively indecent in a motor car4 ,an angle of #a in #aj is the exception on a car1 but it is common on an airplane1 and no one ever heard of a car going down a hill of #aj to #a--which is not quite a vertical dive4 ,therefore1 there is every excuse for a well-designed and properly brought-up carburetor misbehaving itself in an aeroplane4 ,it seems1 then1 that it is up to the manufacturers to produce better carburetors--say1 with the jet central with the float4 ,but it also behooves the user to show ordinary common sense in handling the material at present available1 and not to make a practice of burning up #be1jjj worth or so of airplane just because he is too lazy to turn off his gasoline1 or to have the tail of his machine lifted up while he is tinkering with his engines4 ,,notes ,,on ,,carburetor ,,adjustment ,the modern float feed carburetor is a delicate and nicely balanced appliance that requires a certain amount of attention and care in order to obtain the best results4 ,the adjustments can only be made by one possessing an intelligent knowledge of carburetor construction and must never be made unless the reason for changing the old adjustment is understood4 ,before altering the adjustment of the leading forms of carburetors1 a few hints regarding the quality to be obtained in the mixture should be given some consideration1 as if these are properly understood this knowledge will prove of great assistance in adjusting the vaporizer to give a good working proportion of fuel and air4 ,there is some question regarding the best mixture proportions and it is estimated that gas will be explosive in which the proportions of fuel vapor and air will vary from one part of the former to a wide range included between four and eighteen parts of the latter4 ,a one to four mixture is much too rich1 while the one in eighteen is much too lean to provide positive ignition4 ,a rich mixture should be avoided because the excessive fuel used will deposit carbon and will soot the cylinder walls1 combustion chamber interior1 piston top and valves and also tend to overheat the motor4 ,a rich mixture will also seriously interfere with flexible control of the engine1 as it will choke up on low throttle and run well on open throttle when the full amount of gas is needed4 ,a rich mixture may be quickly discovered by black smoke issuing from the muffler1 the exhaust gas having a very pungent odor4 ,if the mixture contains a surplus of air there will be popping sounds in the carburetor1 which is commonly termed blowing back4 ,to adjust a carburetor is not a difficult matter when the purpose of the various control members is understood4 ,the first thing to do in adjusting a carburetor is to start the motor and to retard the sparking lever so the motor will run slowly leaving the throttle about half open4 ,in order to ascertain if the mixture is too rich cut down the gasoline flow gradually by screwing down the needle valve until the motor commences to run irregularly or misfire4 ,close the needle valves as far as possible without having the engine come to a stop1 and after having found the minimum amount of fuel gradually unscrew the adjusting valve until you arrive at the point where the engine develops its highest speed4 ,when this adjustment is secured the lock nut is screwed in place so the needle valve will keep the adjustment4 ,the next point to look out for is regulation of the auxiliary air supply on those types of carburetors where an adjustable air valve is provided4 ,this is done by advancing the spark lever and opening the throttle4 ,the air valve is first opened or the spring tension reduced to a point where the engine misfires or pops back in the carburetor4 ,when the point of maximum air supply the engine will run on is thus determined1 the air valve spring may be tightened by screwing in on the regulating screw until the point is reached where an appreciable speeding up of the engine is noticed4 ,if both fuel and air valves are set right1 it will be possible to accelerate the engine speed uniformly without interfering with regularity of engine operation by moving the throttle lever or accelerator pedal from its closed to its wide open position1 this being done with the spark lever advanced4 ,all types of carburetors do not have the same means of adjustment2 in fact1 some adjust only with the gasoline regulating needle2 others must have a complete change of spray nozzles2 while in others the mixture proportions may be varied only by adjustment of the quantity of entering air4 ,changing the float level is effective in some carburetors1 but this should never be done unless it is certain that the level is not correct4 ,full instructions for locating carburetion troubles will be given in proper sequence4 ,it is a fact well known to experienced repairmen and motorists that atmospheric conditions have much to do with carburetor action4 ,it is often observed that a motor seems to develop more power at night than during the day1 a circumstance which is attributed to the presence of more moisture in the cooler night air4 ,likewise1 taking a motor from sea level to an altitude of #aj1jjj feet involves using rarefied air in the engine cylinders and atmospheric pressures ranging from #ad4g pounds at sea level to #aj4a pounds per square inch at the high altitude4 ,all carburetors will require some adjustment in the course of any material change from one level to another4 ,great changes of altitude also have a marked effect on the cooling system of an airplane4 ,water boils at #bab degrees ,f4 only at sea level4 ,at an altitude of #aj1jjj feet it will boil at a temperature nineteen degrees lower1 or #aic degrees ,f4 ,in high altitudes the reduced atmospheric pressure1 for #e1jjj feet or higher than sea level1 results in not enough air reaching the mixture1 so that either the auxiliary air opening has to be increased1 or the gasoline in the mixture cut down4 ,if the user is to be continually at high altitudes he should immediately purchase either a larger dome or a smaller strangling tube1 mentioning the size carburetor that is at present in use and the type of motor that it is on1 including details as to the bore and stroke4 ,the smaller strangling tube makes an increased suction at the spray nozzle2 the air will have to be readjusted to meet it and you can use more auxiliary air1 which is necessary4 ,the effect on the motor without a smaller strangling tube is a perceptible sluggishness and failure to speed up to its normal crank-shaft revolutions1 as well as failure to give power4 ,it means that about one-third of the regular speed is cut out4 ,the reduced atmospheric pressure reduces the power of the explosion1 in that there is not the same quantity of oxygen in the combustion chamber as at sea level2 to increase the amount taken in1 you must also increase the gasoline speed1 which is done by an increased suction through the smaller strangling aperture4 ,some forms of carburetors are affected more than others by changes of altitude1 which explains why the ,zenith is so widely employed for airplane engine use4 ,the compensating nozzle construction is not influenced as much by changes of altitude as the simpler nozzle types are4 ,,chapter ,,vi ,early ,ignition ,systems--,electrical ,ignition ,best--,fundamentals of ,magnetism ,outlined--,forms of ,magneto--,zones of ,magnetic ,influence--,how ,magnets are ,made--,electricity and ,magnetism ,related--,basic ,principles of ,magneto ,action--,essential ,parts of ,magneto and ,functions--,transformer ,coil ,systems--,true ,high ,tension ,type--,the ,berling ,magneto--,timing and ,care--,the ,dixie ,magneto--,spark ,plug ,design and ,application--,two-,spark ,ignition-- ,special ,airplane ,plug4 ,,early ,,ignition ,,systems ,one of the most important auxiliary groups of the gasoline engine comprising the airplane power plant and one absolutely necessary to insure engine action is the ignition system or the method employed of kindling the compressed gas in the cylinder to produce an explosion and useful power4 ,the ignition system has been fully as well developed as other parts of the engine1 and at the present time practically all ignition systems follow principles which have become standard through wide acceptance4 ,during the early stages of development of the gasoline engine various methods of exploding the charge of combustible gas in the cylinder were employed4 ,on some of the earliest engines a flame burned close to the cylinder head1 and at the proper time for ignition a slide or valve moved to provide an opening which permitted the flame to ignite the gas back of the piston4 ,this system was practical only on the primitive form of gas engines in which the charge was not compressed before ignition4 ,later1 when it was found desirable to compress the gas a certain degree before exploding it1 an incandescent platinum tube in the combustion chamber1 which was kept in a heated condition by a flame burning in it1 exploded the gas4 ,the naked flame was not suitable in this application because when the slide was opened to provide communication between the flame and the gas the compressed charge escaped from the cylinder with enough pressure to blow out the flame at times and thus cause irregular ignition4 ,when the flame was housed in a platinum tube it was protected from the direct action of the gas1 and as long as the tube was maintained at the proper point of incandescence regular ignition was obtained4 ,some engineers utilized the property of gases firing themselves if compressed to a sufficient degree1 while others depended upon the heat stored in the cylinder-head to fire the highly compressed gas4 ,none of these methods were practical in their application to motor car engines because they did not permit flexible engine action which is so desirable4 ,at the present time1 electrical ignition systems in which the compressed gas is exploded by the heating value of the minute electric arc or spark in the cylinder are standard1 and the general practice seems to be toward the use of mechanical producers of electricity rather than chemical batteries4 ,,electrical ,,ignition ,,best ,two general forms of electrical ignition systems may be used1 the most popular being that in which a current of electricity under high tension is made to leap a gap or air space between the points of the sparking plug screwed into the cylinder4 ,the other form1 which has been almost entirely abandoned in automobile and which was never used with airplane engine practice1 but which is still used to some extent on marine engines1 is called the low-tension system because current of low voltage is used and the spark is produced by moving electrodes in the combustion chamber4 ,the essential elements of any electrical ignition system1 either high or low tension1 are3 ,first1 a simple and practical method of current production2 second1 suitable timing apparatus to cause the spark to occur at the right point in the cycle of engine action2 third1 suitable wiring and other apparatus to convey the current produced by the generator to the sparking member in the cylinder4 ,the various appliances necessary to secure prompt ignition of the compressed gases should be described in some detail because of the importance of the ignition system4 ,it is patent that the scope of a work of this character does not permit one to go fully into the theory and principles of operation of all appliances which may be used in connection with gasoline motor ignition1 but at the same time it is important that the elementary principles be considered to some extent in order that the reader should have a proper understanding of the very essential ignition apparatus4 ,the first point considered will be the common methods of generating the electricity1 then the appliances to utilize it and produce the required spark in the cylinder4 ,inasmuch as magneto ignition is universally used in connection with airplane engine ignition it will not be necessary to consider battery ignition systems4 ,,fundamentals ,,of ,,magnetism ,,outlined ,to properly understand the phenomena and forces involved in the generation of electrical energy by mechanical means it is necessary to become familiar with some of the elementary principles of magnetism and its relation to electricity4 ,the following matter can be read with profit by those who are not familiar with the subject4 ,most persons know that magnetism exists in certain substances1 but many are not able to grasp the terms used in describing the operation of various electrical devices because of not possessing a knowledge of the basic facts upon which the action of such apparatus is based4 ,magnetism is a property possessed by certain substances and is manifested by the ability to attract and repel other materials susceptible to its effects4 ,when this phenomenon is manifested by a conductor or wire through which a current of electricity is flowing it is termed electro-magnetism4 ,magnetism and electricity are closely related1 each being capable of producing the other4 ,practically all of the phenomena manifested by materials which possess magnetic qualities naturally can be easily reproduced by passing a current of electricity through a body which1 when not under electrical influence1 is not a magnetic substance4 ,only certain substances show magnetic properties1 these being iron1 nickel1 cobalt and their alloys4 ,the earliest known substance possessing magnetic properties was a stone first found in ,asia ,minor4 ,it was called the lodestone or leading stone1 because of its tendency1 if arranged so it could be moved freely1 of pointing one particular portion toward the north4 ,the compass of the ancient ,chinese mariners was a piece of this material1 now known to be iron ore1 suspended by a light thread or floated on a cork in some liquid so one end would point toward the north magnetic pole of the earth4 ,the reason that this stone was magnetic was hard to define for a time1 until it was learned that the earth was one huge magnet and that the iron ore1 being particularly susceptible1 absorbed and retained some of this magnetism4 ,most of us are familiar with some of the properties of the magnet because of the extensive sale and use of small horseshoe magnets as toys4 ,as they only cost a few pennies every one has owned one at some time or other and has experimented with various materials to see if they would be attracted4 ,small pieces of iron or steel were quickly attracted to the magnet and adhered to the pole pieces when brought within the zone of magnetic influence4 ,it was soon learned that brass1 copper1 tin or zinc were not affected by the magnet4 ,a simple experiment that serves to illustrate magnetic attraction of several substances is shown at ,a1 ,fig4 #eg4 ,in this1 several balls are hung from a standard or support1 one of these being of iron1 another of steel4 ,when a magnet is brought near either of these they will be attracted toward it1 while the others will remain indifferent to the magnetic force4 ,experimenters soon learned that of the common metals only iron or steel were magnetic4 ,illustration3 ,fig4 #eg4--,some ,simple ,experiments to ,demonstrate ,various ,magnetic ,phenomena and ,clearly ,outline ,effects of ,magnetism and ,various ,forms of ,magnets4 ,if the ordinary bar or horseshoe magnet be carefully examined1 one end will be found to be marked ,n4 ,this indicates the north pole1 while the other end is not usually marked and is the south pole4 ,if the north pole of one magnet is brought near the south pole of another1 a strong attraction will exist between them1 this depending upon the size of the magnets used and the air gap separating the poles4 ,if the south pole of one magnet is brought close to the end of the same polarity of the other there will be a pronounced repulsion of like force4 ,these facts are easily proved by the simple experiment outlined at ,b1 ,fig4 #eg4 ,a magnet will only attract or influence a substance having similar qualities4 ,the like poles of magnets will repel each other because of the obvious impossibility of uniting two influences or forces of practically equal strength but flowing in opposite directions4 ,the unlike poles of magnets attract each other because the force is flowing in the same direction4 ,the flow of magnetism is through the magnet from south to north and the circuit is completed by the flow of magnetic influence through the air gap or metal armature bridging it from the north to the south pole4 ,,forms ,,of ,,magnets ,,and ,,zone ,,of ,,magnetic ,,influence ,,defined ,magnets are commonly made in two forms1 either in the shape of a bar or horseshoe4 ,these two forms are made in two types1 simple or compound4 ,the latter are composed of a number of magnets of the same form united so the ends of like polarity are laced together1 and such a construction will be more efficient and have more strength than a simple magnet of the same weight4 ,the two common forms of simple and compound magnets are shown at ,c1 ,fig4 #eg4 ,the zone in which a magnetic influence occurs is called the magnetic field1 and this force can be graphically shown by means of imaginary lines1 which are termed lines of force4 ,as will be seen from the diagram at ,d1 ,fig4 #eg1 the lines show the direction of action of the magnetic force and also show its strength1 as they are closer together and more numerous when the intensity of the magnetic field is at its maximum4 ,a simple method of demonstrating the presence of the force is to lay a piece of thin paper over the pole pieces of either a bar or horseshoe magnet and sprinkle fine iron filings on it4 ,the particles of metal arrange themselves in very much the manner shown in the illustrations and prove that the magnetic field actually exists4 ,the form of magnet used will materially affect the size and area of the magnetic field4 ,it will be noted that the field will be concentrated to a greater extent with the horseshoe form because of the proximity of the poles4 ,it should be understood that these lines have no actual existence1 but are imaginary and assumed to exist only to show the way the magnetic field is distributed4 ,the magnetic influence is always greater at the poles than at the center1 and that is why a horseshoe or ,u-form magnet is used in practically all magnetos or dynamos4 ,this greater attraction at the poles can be clearly demonstrated by sprinkling iron filings on bar and ,u magnets1 as outlined at ,e1 ,fig4 #eg4 ,a large mass gathers at the pole pieces1 gradually tapering down toward the point where the attraction is least4 ,from the diagrams it will be seen that the flow of magnetism is from one pole to the other by means of curved paths between them4 ,this circuit is completed by the magnetism flowing from one pole to the other through the magnet1 and as this flow is continued as long as the body remains magnetic it constitutes a magnetic circuit4 ,if this flow were temporarily interrupted by means of a conductor of electricity moving through the field there would be a current of electricity induced in the conductor every time it cut the lines of force4 ,there are three kinds of magnetic circuits4 ,a non-magnetic circuit is one in which the magnetic influence completes its circuit through some substance not susceptible to the force4 ,a closed magnetic circuit is one in which the influence completes its circuit through some magnetic material which bridges the gap between the poles4 ,a compound circuit is that in which the magnetic influence passes through magnetic substances and non-magnetic substances in order to complete its circuit4 ,,how ,,iron ,,and ,,steel ,,bars ,,are ,,made ,,magnetic ,magnetism may be produced in two ways1 by contact or induction4 ,if a piece of steel is rubbed on a magnet it will be found a magnet when removed1 having a north and south pole and all of the properties found in the energizing magnet4 ,this is magnetizing by contact4 ,a piece of steel will retain the magnetism imparted to it for a considerable length of time1 and the influence that remains is known as residual magnetism4 ,this property may be increased by alloying the steel with tungsten and hardening it before it is magnetized4 ,any material that will retain its magnetic influence after removal from the source of magnetism is known as a permanent magnet4 ,if a piece of iron or steel is brought into the magnetic field of a powerful magnet it becomes a magnet without actual contact with the energizer4 ,this is magnetizing by magnetic induction4 ,if a powerful electric current flows through an insulated conductor wound around a piece of iron or steel it will make a magnet of it4 ,this is magnetizing by electro-magnetic induction4 ,a magnet made in this manner is termed an electro-magnet and usually the metal is of such a nature that it will not retain its magnetism when the current ceases to flow around it4 ,steel is used in all cases where permanent magnets are required1 while soft iron is employed in all cases where an intermittent magnetic action is desired4 ,magneto field magnets are always made of tungsten steel alloy1 so treated that it will retain its magnetism for lengthy periods4 ,,electricity ,,and ,,magnetism ,,closely ,,related ,there are many points in which magnetism and electricity are alike4 ,for instance1 air is a medium that offers considerable resistance to the passage of both magnetic influence and electric energy1 although it offers more resistance to the passage of the latter4 ,minerals like iron or steel are very easily influenced by magnetism and easily penetrated by it4 ,when one of these is present in the magnetic circuit the magnetism will flow through the metal4 ,any metal is a good conductor for the passage of the electric current1 but few metals are good conductors of magnetic energy4 ,a body of the proper metal will become a magnet due to induction if placed in the magnetic field1 having a south pole where the lines of force enter it and a north pole where they pass out4 ,we have seen that a magnet is constantly surrounded by a magnetic field and that an electrical conductor when carrying a current is also surrounded by a field of magnetic influence4 ,now if the conductor carrying a current of electricity will induce magnetism in a bar of iron or steel1 by a reversal of this process1 a magnetized iron or steel bar will produce a current of electricity in a conductor4 ,it is upon this principle that the modern dynamo or magneto is constructed4 ,if an electro-motive force is induced in a conductor by moving it across a field of magnetic influence1 or by passing a magnetic field near a conductor1 electricity is said to be generated by magneto-electric induction4 ,all mechanical generators of the electric current using permanent steel magnets to produce a field of magnetic influence are of this type4 ,,basic ,,principles ,,of ,,magneto ,,outlined ,the accompanying diagram1 ,fig4 #eh1 will show these principles very clearly4 ,as stated on an earlier page1 if the lines of force in the magnetic field are cut by a suitable conductor an electrical impulse will be produced in that conductor4 ,in this simple machine the lines of force exist between the poles of a horseshoe magnet4 ,the conductor1 which in this case is a loop of copper wire1 is mounted upon a spindle in order that it may be rotated in the magnetic field to cut the lines of magnetic influence present between the pole pieces4 ,both of the ends of this loop are connected1 one with the insulated drum shown upon the shaft1 the other to the shaft4 ,two metal brushes are employed to collect the current and cause it to flow through the external circuit4 ,it can be seen that when the shaft is turned in the direction of the arrow the loop will cut through the lines of magnetic influence and a current will be generated therein4 ,illustration3 ,fig4 #eh4--;,elementary ,form of ,magneto ,showing ,principal ,parts ,simplified to ,make ,method of ,current ,generation ,clear4 ,the pressure of the current and the amount produced vary in accordance to the rapidity with which the lines of magnetic influence are cut4 ,the armature of a practical magneto1 therefore1 differs materially from that shown in the diagram4 ,a large number of loops of wire would be mounted upon this shaft in order that the lines of magnetic influence would be cut a greater number of times in a given period and a core of iron used as a backing for the wire4 ,this would give a more rapid alternating current and a higher electro-motive force than would be the case with a smaller number of loops of wire4 ,illustration3 ,fig4 #ei4--,showing ,how ,strength of ,magnetic ,influence and of the ,currents ,induced in the ,windings of ,armature ,vary with the ,rapidity of ,changes of ,flow4 ,the illustrations at ,fig4 #ei show a conventional double winding armature and field magnetic of a practical magneto in part section and will serve to more fully emphasize the points previously made4 ,if the armature or spindle were removed from between the pole pieces there would exist a field of magnetic influence as shown at ,fig4 #eg1 but the introduction of this component provides a conductor 7the iron core7 for the magnetic energy1 regardless of its position1 though the facility with which the influence will be transmitted depends entirely upon the position of the core4 ,as shown at ,a1 the magnetic flow is through the main body in a straight line1 while at ,b1 which position the armature has attained after one-eighth revolution1 or #de degrees travel in the direction of the arrow1 the magnetism must pass through in the manner indicated4 ,at ,c1 which position is attained every half revolution1 the magnetic energy abandons the longer path through the body of the core for the shorter passage offered by the side pieces1 and the field thrown out by the cross bar disappears4 ,on further rotation of the armature1 as at ,d1 the body of the core again becomes energized as the magnetic influence resumes its flow through it4 ,these changes in the strength of the magnetic field when distorted by the armature core1 as well as the intensity of the energy existing in the field1 affect the windings1 and the electrical energy induced therein corresponds in strength to the rapidity with which these changes in magnetic flow occur4 ,the most pronounced changes in the strength of the field will occur as the armature passes from position ,b to ,d1 because the magnetic field existing around the core will be destroyed and again re-established4 ,during the most of the armature rotation the changes in strength will be slight and the currents induced in the wire correspondingly small2 but at the instant the core becomes remagnetized1 as the armature leaves position ,c1 the current produced will be at its maximum1 and it is necessary to so time the rotation of the armature that at this instant one of the cylinders is in condition to be fired4 ,it is imperative that the armature be driven in such relation to the crank-shaft that each production of maximum current coincides with the ignition point1 this condition existing twice during each revolution of the armature1 or at every #ahj degrees travel4 ,each position shown corresponds to #de degrees travel of the armature1 or one-eighth of a turn1 and it takes just three-eighths revolution to change the position from ,a to that shown at ,d4 ,,essential ,,parts ,,of ,a ,,magneto ,,and ,,their ,,functions ,the magnets which produce the influence that in turn induces the electrical energy in the winding or loops of wire on the armature1 and which may have any even number of opposed poles1 are called field magnets4 ,the loops of wire which are mounted upon a suitable drum and rotate in the field of magnetic influence in order to cut the lines of force is called an armature winding1 while the core is the metal portion4 ,the entire assembly is called the armature4 ,the exposed ends of the magnets are called pole pieces and the arrangement used to collect the current is either a commutator or a collector4 ,the stationary pieces which bear against the collector or commutator and act as terminals for the outside circuit are called brushes4 ,these brushes are often of copper1 or some of its alloys1 because copper has a greater electrical conductivity than any other metal4 ,these brushes are nearly always of carbon1 which is sometimes electroplated with copper to increase its electrical conductivity1 though cylinders of copper wire gauze impregnated with graphite are utilized at times4 ,carbon is used because it is not so liable to cut the metal of the commutator as might be the case if the contact was of the metal to metal type4 ,the reason for this is that carbon has the peculiar property in that it materially assists in the lubrication of the commutator1 and being of soft1 unctuous composition1 will wear and conform to any irregularities on the surface of the metal collector rings4 ,the magneto in common use consists of a number of horseshoe magnets which are compound in form and attached to suitable cast-iron pole pieces used to collect and concentrate the magnetic influence of the various magnets4 ,between these pole pieces an armature rotates4 ,this is usually shaped like a shuttle1 around which are wound coils of insulated wire4 ,these are composed of a large number of turns and the current produced depends in great measure upon the size of the wire and the number of turns per coil4 ,an armature winding of large wire will deliver a current of great amperage1 but of small voltage4 ,an armature wound with very fine wire will deliver a current of high voltage but of low amperage4 ,in the ordinary form of magneto1 such as used for ignition1 the current is alternating in character and the break in the circuit should be timed to occur when the armature is at the point of its greatest potential or pressure4 ,where such a generator is designed for direct current production the ends of the winding are attached to the segments of a commutator1 but where the instrument is designed to deliver an alternating current one end of the winding is fastened to an insulator ring on one end of the armature shaft and the other end is grounded on the frame of the machine4 ,the quantity of the current depends upon the strength of the magnetic field and the number of lines of magnetic influence acting through the armature4 ,the electro-motive force varies as to the length of the armature winding and the number of revolutions at which the armature is rotated4 ,,the ,,transformer ,,system ,,uses ,,low ,,voltage ,,magneto ,the magneto in the various systems which employ a transformer coil is very similar to a low-tension generator in general construction1 and the current delivered at the terminals seldom exceeds #ajj volts4 ,as it requires many times that potential or pressure to leap the gap which exists between the points of the conventional spark plug1 a separate coil is placed in circuit to intensify the current to one of greater capacity4 ,the essential parts of such a system and their relation to each other are shown in diagrammatic form at ,fig4 #fj and as a complete system at ,fig4 #fa4 ,as is true of other systems the magnetic influence is produced by permanent steel magnets clamped to the cast-iron pole pieces between which the armature rotates4 ,at the point of greatest potential in the armature winding the current is broken by the contact breaker1 which is actuated by a cam1 and a current of higher value is induced in the secondary winding of the transformer coil when the low voltage current is passed through the primary winding4 ,illustration3 ,fig4 #fj4--;,diagrams ,explaining ,action of ,low ,tension ,transformer ,coil and ,true ,high ,tension ,magneto ,ignition ,systems4 ,illustration3 ,fig4 #fj;,a4--,side ,sectional ,view of ,bosch ,high-,tension ,magneto ,shows ,disposition of ,parts4 ,end ,elevation ,depicts ,arrangement of ,interruptor and ,distributor ,mechanism4 ,it will be noted that the points of the contact breaker are together except for the brief instant when separated by the action of the point of the cam upon the lever4 ,it is obvious that the armature winding is short-circuited upon itself except when the contact points are separated4 ,while the armature winding is thus short-circuited there will be practically no generation of current4 ,when the points are separated there is a sudden flow of current through the primary winding of the transformer coil1 inducing a secondary current in the other winding1 which can be varied in strength by certain considerations in the preliminary design of the apparatus4 ,this current of higher potential or voltage is conducted directly to the plug if the device is fitted to a single-cylinder engine1 or to the distributor arm if fitted to a multiple-cylinder motor4 ,the distributor consists of an insulator in which is placed a number of segments1 one for each cylinder to be fired1 and so spaced that the number of degrees between them correspond to the ignition points of the motor4 ,a two-cylinder motor would have two segments1 a three-cylinder1 three segments1 and so on within the capacity of the instrument4 ,in the illustration a four-cylinder distributor is fitted1 and the distributing arm is in contact with the segment corresponding to the cylinder about to be fired4 ,illustration3 ,fig4 #fa4--;,berling ,two-,spark ,dual ,ignition ,system4 ,,true ,,high-,,tension ,,magnetos ,,are ,,self-,,contained ,illustration3 ,fig4 #fb4--;,berling ,double-,spark ,independent ,system4 ,the true high-tension magneto differs from the preceding inasmuch as the current of high voltage is produced in the armature winding direct1 without the use of the separate coil4 ,instead of but one coil1 the armature carries two1 one of comparatively coarse wire1 the other of many turns of finer wire4 ,the arrangement of these windings can be readily ascertained by reference to the diagram ,b1 ,fig4 #fj1 which shows the principle of operation very clearly4 ,the simplicity of the ignition system is evident by inspection of ,fig4 #fb4 ,one end of the primary winding 7coarse wire7 is coupled or grounded to the armature core1 and the other passes to the insulated part of the interrupter4 ,while in some forms the interrupter or contact breaker mechanism does not revolve1 the desired motion being imparted to the contact lever to separate the points of a revolving cam1 in this the cam or tripping mechanism is stationary and the contact breaker revolves4 ,this arrangement makes it possible to conduct the current from the revolving primary coil to the interrupter by a direct connection1 eliminating the use of brushes1 which would otherwise be necessary4 ,in other forms of this appliance where the winding is stationary1 the interrupter may be operated by a revolving cam1 though1 if desired1 the used of a brush at this point will permit this construction with a revolving winding4 ,during the revolution of the armature the grounded lever makes and breaks contact with the insulated point1 short-circuiting the primary winding upon itself until the armature reaches the proper position of maximum intensity of current production1 at which time the circuit is broken1 as in the former instance4 ,one end of the secondary winding 7fine wire7 is grounded on the live end of the primary1 the other end being attached to the revolving arm of the distributor mechanism4 ,so long as a closed circuit is maintained feeble currents will pass through the primary winding1 and so long as the contact points are together this condition will exist4 ,when the current reaches its maximum value1 because of the armature being in the best position1 the cam operates the interrupter and the points are separated1 breaking the short circuit which has existed in the primary winding4 ,the secondary circuit has been open while the distributor arm has moved from one contact to another and there has been no flow of energy through this winding4 ,while the electrical pressure will rise in this1 even if the distributor arm contacted with one of the segments1 there would be no spark at the plug until the contact points separated1 because the current in the secondary winding would not be of sufficient strength4 ,when the interrupter operates1 however1 the maximum primary current will be diverted from its short circuit and can flow to the ground only through the secondary winding and spark-plug circuit4 ,the high pressure now existing in the secondary winding will be greatly increased by the sudden flow of primary current1 and energy of high enough potential to successfully bridge the gap at the plug is thereby produced in the winding4 ,,the ,,berling ,,magneto ,illustration3 ,fig4 #fc4--,type ,,dd ,berling ,high ,tension ,magneto4 ,the ,berling magneto is a true high tension type delivering two impulses per revolution1 but it is made in a variety of forms1 both single and double spark4 ,its principle of action does not differ in essentials from the high tension type previously described4 ,this magneto is used on ,curtiss aviation engines and will deliver sparks in a positive manner sufficient to insure ignition of engines up to #bjj horse-power and at rotative speeds of the magneto armature up to #d1jjj r4 p4 m4 which is sufficient to take care of an eight-cylinder ,v engine running up to #b1jjj r4 p4 m4 ,the magneto is driven at crank-shaft speed on four-cylinder engines1 at #a-a_/b times crank-shaft speed on six-cylinder engines and at twice crank-shaft speed on eight-cylinder ,v types4 ,the types ,d and ,,dd ,,berling ,magnetos are interchangeable with corresponding magnetos of other standard makes4 ,the dimensions of the four-1 six- and eight-cylinder types ,d and ,,dd are all the same4 ,the ideal method of driving the magneto is by means of flexible direct connecting coupling to a shaft intended for the purpose of driving the magneto4 ,as the magneto must be driven at a high speed1 a coupling of some flexibility is preferable4 ,the employment of such a coupling will facilitate the mounting of the magneto1 because a small inaccuracy in the lining up of the magneto with the driving shaft will be taken care of by the flexible coupling1 whereas with a perfectly rigid coupling the line-up of the magneto must be absolutely accurate4 ,another advantage of the flexible coupling is that the vibration of the motor will not be as fully transmitted to the armature shaft on the magneto as in case a rigid coupling is used4 ,this means prolonged life for the magneto4 ,the next best method of driving the magneto is by means of a gear keyed to the armature shaft4 ,when this method of driving is employed1 great care must be exercised in providing sufficient clearance between the gear on the magneto and the driving gear4 ,if there should be a tight spot between these two gears it will react disadvantageously on the magneto4 ,the third available method is to drive the magneto by means of a chain4 ,this is the least desirable of the three methods and should be resorted to only in case of absolute necessity4 ,it is difficult to provide sufficient clearance when using a chain without rendering the timing less accurate and positive4 ,illustration3 ,fig4 #fd4--,wiring ,diagrams of ,berling ,magneto ,ignition ,systems4 ,fig4 #fd1 ,a shows diagrammatically the circuit of the ,d type two-spark independent magneto and the switch used with it4 ,in position ,,off the primary winding of the magneto is short-circuited and in this position the switch serves as an ordinary cut-out or grounding switch4 ,in position #a the switch connects the magneto in such a way that it operates as an ordinary single-spark magneto4 ,in this position one end of the secondary winding is grounded to the body of the motor4 ,this is the starting position4 ,in this position of the switch the entire voltage generated in the magneto is concentrated at one spark-plug instead of being divided in half4 ,with the motor turning over very slowly1 as is the case in starting1 the full voltage generated by the magneto will not in all cases be sufficient to bridge simultaneously two spark gaps1 but is amply sufficient to bridge one4 ,also1 this position of the switch tends to retard the ignition and should be used in starting to prevent back-firing4 ,with the switch in position #b the magneto applies ignition to both plugs in each cylinder simultaneously4 ,this is the normal running position4 ,fig4 #fd1 ,b shows diagrammatically the circuit of the type ,,dd ,,berling high-tension two-spark dual magneto4 ,this type is recommended for certain types of heavy-duty airplane motors1 which it is impossible to turn over fast enough to give the magneto sufficient speed to generate even a single spark of volume great enough to ignite the gas in the cylinder4 ,the dual feature consists of the addition to the magneto of a battery interrupter4 ,the equipment consists of the magneto1 coil and special high-tension switch4 ,the coil is intended to operate on six volts4 ,either a storage battery or dry cells may be used4 ,with the switch in the ,,off position1 the magneto is grounded1 and the battery circuit is open4 ,with the switch in the second or battery position marked ,,bat1 one end of the secondary winding of the magneto is grounded1 and the magneto operates as a single-spark magneto delivering high-tension current to the inside distributor1 and the battery circuit being closed the high-tension current from the coil is delivered to the outside distributor4 ,in this position the battery current is supplied to one set of spark plugs1 no matter how slowly the motor is turned over1 but as soon as the motor starts1 the magneto supplies current as a single-spark magneto to the other set of the spark-plugs4 ,after the engine is running1 the switch should be thrown to the position marked ,,mag4 ,the battery and coil are then disconnected1 and the magneto furnishes ignition to both plugs in each cylinder4 ,this is the normal running position4 ,either a non-vibrating coil type ,n-#a is furnished or a combined vibrating and non-vibrating coil type ,,vn-#a4 ,,setting ,,berling ,,magneto ,the magneto may be set according to one of two different methods1 the selection of which is1 to some extent1 governed by the characteristics of the engine1 but largely due to the personal preference on the part of the user4 ,in the first method described below1 the most advantageous position of the piston for fully advanced ignition is determined in relation to the extreme advanced position of the magneto4 ,in this case1 the fully retarded ignition will not be a matter of selection1 but the timing range of the magneto is wide enough to bring the fully retarded ignition after top-center position of the piston4 ,the second method for the setting of the magneto fixes the fully retarded position of the magneto in relation to that position of the piston where fully retarded ignition is desired4 ,in this case1 the extreme advance position of the magneto will not always correspond with the best position of the piston for fully advanced ignition1 and the amount of advance the magneto should have to meet ideal requirements in this respect must be determined by experiment4 ,first ,method3 #a4 ,designate one cylinder as cylinder ,no4 #a4 #b4 ,turn the crank-shaft until the piston in cylinder ,no4 #a is in the position where the fully advanced spark is desired to occur4 #c4 ,remove the cover from the distributor block and turn the armature shaft in the direction of rotation of the magneto until the distributor finger-brush comes into such a position that this brush makes contact with the segment which is connected to the cable terminal marked #a4 ,this is either one of the two bottom segments1 depending upon the direction of rotation4 #d4 ,place the cam housing in extreme advance1 i4e41 turn the cam housing until it stops1 in the direction opposite to the direction of rotation of the armature4 ,with the cam housing in this position1 open the cover4 #e4 ,with the armature in the approximate position as described in #c1 turn the armature slightly in either direction to such a point that the platinum points of the magneto interrupter will just begin to open at the end of the cam1 adjacent to the fibre lever on the interrupter4 #f4 ,with this exact position of the armature1 fix the magneto to the driving member of the engine4 ,second ,method3 #a4 ,designate one cylinder as cylinder ,no4 #a4 #b4 ,turn the crank-shaft until the piston in cylinder ,no4 #a is in the position at which the fully retarded spark is desired to occur4 #c4 ,same as ,no4 #c under ,first ,method4 #d4 ,place the cam housing in extreme retard1 i4e41 turn the cam housing until it stops1 in the same direction as the direction of rotation of the armature4 ,with the cam housing in this position1 open the cover4 #e4 ,same as ,no4 #e under ,first ,method4 #f4 ,same as ,no4 #f under ,first ,method4 ,,wiring ,,the ,,magneto ,the wiring of the magneto is clearly shown by wiring diagram4 ,first determine the sequence of firing for the cylinders and then connect the cables to the spark plug in the cylinders in proper sequence1 beginning with cylinder ,no4 #a marked on the distributor block4 ,the switch used with the independent type must be mounted in such a manner that there will be a metallic connection between the frame of the magneto and the metal portion of the switch4 ,it is advisable to use a separate battery1 either storage or dry cells1 as a source of current for the dual equipment4 ,connecting to the same battery that is used with the generator and other electrical equipment may cause trouble1 as a ground in this battery causes the coil to overheat4 ,,care ,,and ,,maintenance ,lubrication3 ,use only the very best of oil for the oil cups4 ,put five drops of oil in the oil cup at the driving end of the magneto for every fifty hours of actual running4 ,put five drops of oil in the oil cup at the interrupter end of the magneto1 located at one side of the cam housing1 for every hundred hours of actual running4 ,lubricate the embossed cams in the cam housing with a thin film of vaseline every fifty hours of actual running4 ,wipe off all superfluous vaseline4 ,never use oil in the interrupter4 ,do not lubricate any other part of the interrupter4 ,adjusting the ,interrupter3 ,with the fibre lever in the center of one of the embossed cams1 as at ,fig4 #fe1 the opening between the platinum contacts should be not less than 4#jaf and not more than 4#jbj4 ,the gauge riveted to the adjusting wrench should barely be able to pass between the contacts when fully open4 ,the platinum contacts must be smoothed off with a very fine file4 ,when in closed position1 the platinum contacts should make contact with each other over their entire surfaces4 ,when inspecting the interrupter1 make sure that the ground brush in the back of the interrupter base is making good contact with the surface on which it rubs4 ,cleaning the ,distributor3 ,the distributor block cover should be removed for inspection every twenty-five hours of actual running and the carbon deposit from the distributor finger-brush wiped off the distributor block by rubbing with a rag or piece of waste dipped in gasoline or kerosene4 ,the high-tension terminal brush on the side of the magneto should also be carefully inspected for proper tension4 ,,locating ,,trouble ,trouble in the ignition system is indicated by the motor missing1 stopping entirely1 or by inability to start4 ,it is safe to assume that the trouble is not in the magneto1 and the carburetor1 gasoline supply and spark-plugs should first be investigated4 ,illustration3 ,fig4 #fe4--,the ,berling ,magneto ,breaker ,box ,showing ,contact ,points ,separated and ,interruptor ,lever on ,cam4 ,if the magneto is suspected1 the first thing to do is to determine if it will deliver a spark4 ,to determine this1 disconnect one of the high-tension leads from the spark-plug in one of the cylinders and place it so that there is approximately #a_/af between the terminal and the cylinder frame4 ,open the pet cocks on the other cylinders to prevent the engine from firing and turn over the engine until the piston is approaching the end of the compression stroke in the cylinder from which the cable has been removed4 ,set the magneto in the advance position and rapidly rock the engine over the top-center position1 observing closely if a spark occurs between the end of the high-tension cable and the frame4 ,if the magneto is of the dual type1 the trouble may be either in the magneto or in the battery or coil system1 therefore disconnect the battery and place the switch in the position marked ,,mag4 ,the magneto will then operate as an independent magneto and should spark in the proper manner4 ,after this the battery system should be investigated4 ,to test the operation of the battery and coil1 examine all connections1 making sure that they are clean and tight1 and then with the switch1 in the ,,bat1 rock the piston slowly back and forth4 ,if a type ,,vn-#a coil is used1 a shower of sparks should jump between the high-tension cable terminal and the cylinder frame when the piston is in the correct position for firing4 ,if no spark occurs1 remove the cover from the coil and see that the vibrating tongue is free4 ,if a type ,n-#a coil is used1 a single spark will occur4 ,the battery should furnish six volts when connected to the coil1 and this should also be verified4 ,if the coil still refuses to give a spark and all connections are correct1 the coil should be replaced and the defective coil returned to the manufacturer4 ,if both magneto and coil give a spark when tested as just described1 the spark-plugs should be investigated4 ,to do this1 disconnect the cables and remove the spark-plugs4 ,then reconnect the cables to the plugs and place them so that the frame portions of the plugs are in metallic connection with the frame of the motor4 ,then turn over the motor1 thus revolving the magneto armature1 and see if a spark is produced at the spark gaps of the plugs4 ,the most common defects in spark-plugs are breaking down of the insulation1 fouling due to carbon1 or too large or small a spark gap4 ,to clean the plugs a stiff brush and gasoline should be used4 ,the spark gap should be about #a_/cb and never less than #a_/fd4 ,too small a gap may have been caused by beads of metal forming due to the heat of the spark4 ,too long a gap may have been caused by the points burning off4 ,if the magneto and spark plugs are in good condition and the engine does not run satisfactorily1 the setting should be verified according to instructions previously given1 and1 if necessary1 readjusted4 ,illustration3 ,fig4 #ff4--,the ,dixie ,model #fj for ,six-,cylinder ,airplane ,engine ,ignition4 ,be careful to observe that both the type ,,vn-#a and type ,n-#a coils are so arranged that the spark occurs on the opening of the contacts of the timer4 ,as this is just the reverse of the usual operation1 it should be carefully noted when any change in the setting of the timer is made4 ,the timer on the dual type magneto is adjusted so that the battery spark occurs about #e deg4 later than the magneto spark4 ,this provides an automatic advance as soon as the switch is thrown to the magneto position ,,mag4 ,this relative timing can be easily adjusted by removing the interrupter and shifting the cam in the direction desired4 ,,the ,,dixie ,,magneto ,illustration3 ,fig4 #fg4--;,installation ,dimensions of ,dixie ,model #fj ,magneto4 ,the ,dixie magneto1 shown at ,fig4 #ff1 operates on a different principle than the rotary armature type4 ,it is used on the ,hall-,scott and other aviation engines4 ,in this magneto the rotating member consists of two pieces of magnetic material separated by a non-magnetic center piece4 ,this member constitutes true rotating poles for the magnet and rotates in a field structure1 composed of two laminated field pieces1 riveted between two non-magnetic rings4 ,the bearings for the rotating poles are mounted in steel plates1 which lie against the poles of the magnets4 ,when the magnet poles rotate1 the magnetic lines of force from each magnet pole are carried directly to the field pieces and through the windings1 without reversal through the mass of the rotating member and with only a single air gap4 ,there are no losses by flux reversal in the rotating part1 such as take place in other machines1 and this is said to account for the high efficiency of the instrument4 ,illustration3 ,fig4 #fh4--,the ,rotating ,elements of the ,dixie ,magneto4 ,and this ,mason ,principle involved in the operation of the ,dixie is simplified by a glance at the field structure1 consisting of the non-magnetic rings1 assembled to which are the field pieces between which the rotating poles revolve 7see ,fig4 #fh74 ,rotating between the limbs of the magnets1 these two pieces of magnetic material form true extensions to the poles of the magnets1 and are1 in consequence1 always of the same polarity4 ,it will be seen there is no reversal of the magnetism through them1 and consequently no eddy current or hysteresis losses which are present in the usual rotor or inductor types4 ,the simplicity features of construction stand out prominently here1 in that there are no revolving windings1 a detail entirely differing from the orthodox high-tension instrument4 ,this simplicity becomes instantly apparent when it is found that the circuit breaker1 instead of revolving as it does in other types1 is stationary and that the whole breaker mechanism is exposed by simply turning the cover spring aside and removing cover4 ,this makes inspection and adjustment particularly simple1 and the fact that no special tool is necessary for adjustment of the platinum points--an ordinary small screw-driver is the whole kit of tools needed in the work of disassembling or assembling--is a feature of some value4 ,illustration3 ,fig4 #fi4--,suggestions for ,adjusting and ,dismantling ,dixie ,magneto4 ,a--,screw ,driver ,adjusts ,contact ,points4 ,b--,distributor ,block ,removed4 ,c--,taking off ,magnets4 ,d--,showing ,how ,easily ,condenser and ,high ,tension ,windings are ,removed4 ,with dust- and water-protecting casing removed1 and one of the magnets withdrawn1 as in ,fig4 #fi1 the winding can be seen with its core resting on the field pole pieces and the primary lead attached to its side4 ,an important feature of the high-tension winding is that the heads are of insulating material1 and there is not the tendency for the high-tension current to jump to the side as in the ordinary armature type magneto4 ,the high-tension current is carried to the distributor by means of an insulated block with a spindle1 at one end of which is a spring brush bearing directly on the winding1 thus shortening the path of the high-tension current and eliminating the use of rubber spools and insulating parts4 ,the moving parts of the magneto need never be disturbed if the high-tension winding is to be removed4 ,this winding constitutes all of the magneto windings1 no external spark coil being necessary4 ,the condenser is placed directly above the winding and is easily removable by taking out two screws1 instead of being placed in an armature where it is inaccessible except to an expert1 and where it cannot be replaced except at the factory whence it emanated4 ,,care ,,of ,,the ,,dixie ,,magneto ,the bearings of the magneto are provided with oil cups and a few drops of light oil every #a1jjj miles are sufficient4 ,the breaker lever should be lubricated every #a1jjj miles with a drop of light oil1 applied with a tooth-pick4 ,the proper distance between the platinum points when separated should not exceed 4#jbj or one-fiftieth of an inch4 ,a gauge of the proper size is attached to the screwdriver furnished with the magneto4 ,the platinum contacts should be kept clean and properly adjusted4 ,should the contacts become pitted1 a fine file should be used to smooth them in order to permit them to come into perfect contact4 ,the distributor block should be removed occasionally and inspected for an accumulation of carbon dust4 ,the inside of the distributor block should be cleaned with a cloth moistened with gasoline and then wiped dry with a clean cloth4 ,when replacing the block1 care must be exercised in pushing the carbon brush into the socket4 ,do not pull out the carbon brushes in the distributor because you think there is not enough tension on the small brass springs4 ,in order to obtain the most efficient results1 the normal setting of the spark-plug points should not exceed 4#jbe of an inch1 and it is advisable to have the gap just right before a spark-plug is inserted4 ,the spark-plug electrodes may be easily set by means of the gauge attached to the screwdriver4 ,the setting of the spark-plug points is an important function which is usually overlooked1 with the result that the magneto is blamed when it is not at fault4 ,,timing ,,of ,,the ,,dixie ,,magneto ,illustration3 ,fig4 #fi;,a4--,sectional ,views ,outlining ,construction of ,dixie ,magneto with ,compound ,distributor for ,eight-,cylinder ,engine ,ignition4 ,in order to obtain the utmost efficiency from the engine1 the magneto must be correctly timed to it4 ,this operation is usually performed when the magneto is fitted to the engine at the factory4 ,the correct setting may vary according to individuality of the engine1 and some engines may require an earlier setting in order to obtain the best results4 ,however1 should the occasion arise to retime the magneto1 the procedure is as follows3 ,rotate the crank-shaft of the engine until one of the pistons1 preferably that of cylinder ,no4 #a1 is #a_/af of an inch ahead of the end of the compression stroke4 ,with the timing lever in full retard position1 the driving shaft of the magneto should be rotated in the direction in which it will be driven4 ,the circuit breaker should be closely observed and when the platinum contact points are about to separate1 the drive gear or coupling should be secured to the drive shaft of the magneto4 ,care should be taken not to alter the position of the magneto shaft when tightening the nut to secure the gear or coupling1 after which the magneto should be secured to its base4 ,remove the distributor block and determine which terminal of the block is in contact with the carbon brush of the distributor finger and connect with plug wire leading to ,no4 #a cylinder to this terminal4 ,connect the remaining plug wires in turn according to the proper sequence of firing of the cylinders4 7,see the wiring diagram for a typical six-cylinder engine at ,fig4 #gj47 ,a terminal on the end of the cover spring of the magneto is provided for the purpose of connecting the wire leading to a ground switch for stopping the engine4 ,a special model or type of magneto is made for ,v engines which use a compound distributor construction instead of the simple type on the model illustrated and a different interior arrangement permits the production of four sparks per revolution of the rotors4 ,this makes it possible to run the magneto slower than would be possible with the two-spark form4 ,the application of two compound distributor magnetos of this type to a ,thomas-,morse #ace horse-power motor of the eight-cylinder ,v pattern is clearly shown at ,fig4 #ga4 ,illustration3 ,fig4 #gj4--,wiring ,diagram of ,dixie ,magneto ,installation on ,hall-,scott ,six-,cylinder #abe ,horse-,power ,aeronautic ,motor4 ,,spark-,,plug ,,design ,,and ,,application ,illustration3 ,fig4 #ga4--;,how ,magneto ,ignition is ,installed on ,thomas-,morse #ace ,horse-,power ,motor4 ,with the high-tension system of ignition the spark is produced by a current of high voltage jumping between two points which break the complete circuit1 which would exist otherwise in the secondary coil and its external connections4 ,the spark-plug is a simple device which consists of two terminal electrodes carried in a suitable shell member1 which is screwed into the cylinder4 ,typical spark-plugs are shown in section at ,fig4 #gb and the construction can be easily understood4 ,the secondary wire from the coil is attached to a terminal at the top of a central electrode member1 which is supported in a bushing of some form of insulating material4 ,the type shown at ,a employs a molded porcelain as an insulator1 while that depicted at ,b uses a bushing of mica4 ,the insulating bushing and electrode are housed in a steel body1 which is provided with a screw thread at the bottom1 by which means it is screwed into the combustion chamber4 ,illustration3 ,fig4 #gb4--,spark-,plug ,types ,showing ,construction and ,arrangement of ,parts4 ,when porcelain is used as an insulating material it is kept from direct contact with the metal portion by some form of yielding packing1 usually asbestos4 ,this is necessary because the steel and porcelain have different coefficients of expansion and some flexibility must be provided at the joints to permit the materials to expand differently when heated4 ,the steel body of the plug which is screwed into the cylinder is in metallic contact with it and carries sparking points which form one of the terminals of the air gap over which the spark occurs4 ,the current entering at the top of the plug cannot reach the ground1 which is represented by the metal portion of the engine1 until it has traversed the full length of the central electrode and overcome the resistance of the gap between it and the terminal point on the shell4 ,the porcelain bushing is firmly seated against the asbestos packing by means of a brass screw gland which sets against a flange formed on the porcelain1 and which screws into a thread at the upper portion of the plug body4 ,the mica plug shown at ,b is somewhat simpler in construction than that shown at ,a4 ,the mica core which keeps the central electrode separated from the steel body is composed of several layers of pure sheet mica wound around the steel rod longitudinally1 and hundreds of stamped steel washers which are forced over this member and compacted under high pressure with some form of a binding material between them4 ,porcelain insulators are usually molded from high-grade clay and are approximately of the shapes desired by the designers of the plug4 ,the central electrode may be held in place by mechanical means such as nuts1 packings1 and a shoulder on the rod1 as shown at ,a4 ,another method sometimes used is to cement the electrode in place by means of some form of fire-clay cement4 ,whatever method of fastening is used1 it is imperative that the joints be absolutely tight so that no gas can escape at the time of explosion4 ,porcelain is the material most widely used because it can be glazed so that it will not absorb oil1 and it is subjected to such high temperature in baking that it is not liable to crack when heated4 ,the spark-plugs may be screwed into any convenient part of the combustion chamber1 the general practice being to install them in the caps over the inlet valves1 or in the side of the combustion chamber1 so the points will be directly in the path of the entering fresh gases from the carburetor4 ,other insulating materials sometimes used are glass1 steatite 7which is a form of soapstone7 and lava4 ,mica and porcelain are the two common materials used because they give the best results4 ,glass is liable to crack1 while lava or the soapstone insulating bushings absorb oil4 ,the spark gap of the average plug is equal to about #a_/cb of an inch for coil ignition and #a_/dj of an inch when used in magneto circuits4 ,a simple gauge for determining the gap setting is the thickness of an ordinary visiting card for magneto plugs1 or a space equal to the thickness of a worn dime for a coil plug4 ,the insulating bushings are made in a number of different ways1 and while details of construction vary1 spark-plugs do not differ essentially in design4 ,the dimensions of the standardized plug recommended by the ,s4 ,a4 ,e4 are shown at ,fig4 #gc4 ,illustration3 ,fig4 #gc4--,standard ,airplane ,engine ,plug ,suggested by ,s4 ,a4 ,e4 ,standards ,committee4 ,it is often desirable to have a water-tight joint between the high-tension cable and the terminal screw on top of the insulating bushing of the spark-plug1 especially in marine applications4 ,the plug shown at ,c1 ,fig4 #gb1 is provided with an insulating member or hood of porcelain1 which is secured by a clip in such a manner that it makes a water-tight connection4 ,should the porcelain of a conventional form of plug become covered with water or dirty oil1 the high-tension current is apt to run down this conducting material on the porcelain and reach the ground without having to complete its circuit by jumping the air gap and producing a spark4 ,it will be evident that wherever a plug is exposed to the elements1 which is often the case in airplane service1 that it should be protected by an insulating hood which will keep the insulator dry and prevent short circuiting of the spark4 ,the same end can be attained by slipping an ordinary rubber nipple over the porcelain insulator of any conventional plug and bringing up one end over the cable4 ,,two-,,spark ,,ignition ,on most aviation engines1 especially those having large cylinders1 it is sometimes difficult to secure complete combustion by using a single-spark plug4 ,if the combustion is not rapid the efficiency of the engine will be reduced proportionately4 ,the compressed charge in the cylinder does not ignite all at once or instantaneously1 as many assume1 but it is the strata of gas nearest the plug which is ignited first4 ,this in turn sets fire to consecutive layers of the charge until the entire mass is aflame4 ,one may compare the combustion of gas in the gas-engine cylinder to the phenomenon which obtains when a heavy object is thrown into a pool of still water4 ,first a small circle is seen at the point where the object has passed into the water1 this circle in turn inducing other and larger circles until the whole surface of the pool has been agitated from the one central point4 ,the method of igniting the gas is very similar1 as the spark ignites the circle of gas immediately adjacent to the sparking point1 and this circle in turn ignites a little larger one concentric with it4 ,the second circle of flame sets fire to more of the gas1 and finally the entire contents of the combustion chamber are burning4 ,while ordinarily combustion is sufficiently rapid with a single plug so that the proper explosion is obtained at moderate engine speeds1 if the engine is working fast and the cylinders are of large capacity more power may be obtained by setting fire to the mixture at two different points instead of but one4 ,this may be accomplished by using two sparking-plugs in the cylinder instead of one1 and experiments have shown that it is possible to gain from twenty-five to thirty per cent4 in motor power at high speed with two-spark plugs1 because the combustion of gas is accelerated by igniting the gas simultaneously in two places4 ,the double-plug system on airplane engines is also a safeguard1 as in event of failure of one plug in the cylinder the other would continue to fire the gas1 and the engine will continue to function properly4 ,in using magneto ignition some precautions are necessary relating to wiring and also the character of the spark-plugs employed4 ,the conductor should be of good quality1 have ample insulation1 and be well protected from accumulations of oil1 which would tend to decompose rubber insulation4 ,it is customary to protect the wiring by running it through the conduits of fiber or metal tubing lined with insulating material4 ,multiple strand cables should be used for both primary and secondary wiring1 and the insulation should be of rubber at least #c_/af inch thick4 ,the spark-plugs commonly used for battery and coil ignition cannot always be employed when a magneto is fitted4 ,the current produced by the mechanical generator has a greater amperage and more heat value than that obtained from transformer coils excited by battery current4 ,the greater heat may burn or fuse the slender points used on some battery plugs and heavier electrodes are needed to resist the heating effect of the more intense arc4 ,while the current has greater amperage it is not of as high potential or voltage as that commonly produced by the secondary winding of an induction coil1 and it cannot overcome as much of a gap4 ,manufacturers of magneto plugs usually set the spark points about #a_/fd of an inch apart4 ,the most efficient magneto plug has a plurality of points so that when the distance between one set becomes too great the spark will take place between one of the other pairs of electrodes which are not separated by so great an air space4 ,illustration3 ,fig4 #gd4--,special ,mica ,plug for ,aviation ,engines4 ,,special ,,plugs ,,for ,,airplane ,,work ,airplane work calls for special construction of spark-plugs1 owing to the high compression used in the engines and the fact that they are operated on open throttle practically all the time1 thus causing a great deal of heat to be developed4 ,the plug shown at ,fig4 #gd was recently described in ,the ,automobile1 and has been devised especially for airplane engines and automobile racing power plants4 ,the core ,c is built up of mica washers1 and has square shoulders4 ,as mica washers of different sizes may be used1 and accurate machining1 such as is necessary with conical clamping surfaces1 is not required1 the plug can be produced economically4 ,the square shoulders of the core afford two gasket seats1 and when the core is clamped in the shell by means of check nut ,e1 it is accurately centered and a tight joint is formed4 ,this construction also makes a shorter plug than where conical fits are used1 thus improving the heat radiation through the stem4 ,the lower end of the shell is provided with a baffle plate ,o1 which tends to keep the oil away from the mica4 ,there are perforations ,l in this baffle plate to prevent burnt gases being pocketed behind the baffle plate and pre-igniting the new charge4 ,this construction also brings the firing point out into the firing chamber of the engine1 and has all the other advantages of a closed-end plug4 ,the stem ,p is made of brass or copper1 on account of their superior heat conductivity1 and the electrode ,j is swedged into the bottom of the stem1 as shown at ,k1 in a secure manner4 ,the shell is finned1 as shown at ,g1 to provide greater heat radiating surface4 ,there is also a fin ,f at the top of the stem1 to increase the radiation of heat from the stem and electrode4 ,the top of this finned portion is slightly countersunk1 and the stem is riveted into same1 thereby reducing the possibility of leakage past the threads on the stem4 ,this finned portion is necked at ,a to take a slip terminal4 ,in building up the core a small section of washers1 ,i1 is built up before the mica insulating tube ,d is placed on4 ,this construction gives a better support to section ,i4 ,baffle plate ,o is bored out to allow the electrode ,j to pass through1 and the clearance between baffle plate and electrode is made larger than the width of the gap between the firing points1 so that there is no danger of the spark jumping from the electrode to the baffle plate4 ,this plug will be furnished either with or without the finned portion1 to meet individual requirements4 ,the manufacturers lay special stress upon the simplicity of construction and upon the method of clamping1 which is claimed to make the plug absolutely gas-tight4 ,,chapter ,,vii ,why ,lubrication ,is ,necessary--,friction ,defined--,theory of ,lubrication--,derivation of ,lubricants--,properties of ,cylinder ,oils--,factors ,influencing ,lubrication ,system ,selection--,gnome ,type ,engines ,use ,castor ,oil--,hall-,scott ,lubrication ,system--,oil ,supply by ,constant ,level ,splash ,system--,dry ,crank-,case ,system ,best for ,airplane ,engines--,why ,cooling ,systems ,are ,necessary-- ,cooling ,systems ,generally ,applied--,cooling by ,positive ,pump ,circulation--,thermo-,syphon ,system--,direct ,air-,cooling ,methods-- ,air-,cooled ,engine ,design ,considerations4 ,,why ,,lubrication ,,is ,,necessary ,the importance of minimizing friction at the various bearing surfaces of machines to secure mechanical efficiency is fully recognized by all mechanics1 and proper lubricity of all parts of the mechanism is a very essential factor upon which the durability and successful operation of the motor car power plant depends4 ,all of the moving members of the engine which are in contact with other portions1 whether the motion is continuous or intermittent1 of high or low velocity1 or of rectilinear or continued rotary nature1 should be provided with an adequate supply of oil4 ,no other assemblage of mechanism is operated under conditions which are so much to its disadvantage as the motor car1 and the tendency is toward a simplification of oiling methods so that the supply will be ample and automatically applied to the points needing it4 ,in all machinery in motion the members which are in contact have a tendency to stick to each other1 and the very minute projections which exist on even the smoothest of surfaces would have a tendency to cling or adhere to each other if the surfaces were not kept apart by some elastic and unctuous substance4 ,this will flow or spread out over the surfaces and smooth out the inequalities existing which tend to produce heat and retard motion of the pieces relative to each other4 ,a general impression which obtains is that well machined surfaces are smooth1 but while they are apparently free from roughness1 and no projections are visible to the naked eye1 any smooth bearing surface1 even if very carefully ground1 will have a rough appearance if examined with a magnifying glass4 ,an exaggerated condition to illustrate this point is shown at ,fig4 #ge4 ,the amount of friction will vary in proportion to the pressure on the surfaces in contact and will augment as the loads increase2 the rougher surfaces will have more friction than smoother ones and soft bodies will produce more friction than hard substances4 ,,friction ,,defined ,friction is always present in any mechanism as a resisting force that tends to retard motion and bring all moving parts to a state of rest4 ,the absorption of power by friction may be gauged by the amount of heat which exists at the bearing points4 ,friction of solids may be divided into two classes3 sliding friction1 such as exists between the piston and cylinder1 or the bearings of a gas-engine1 and rolling friction1 which is that present when the load is supported by ball or roller bearings1 or that which exists between the tires or the driving wheels and the road4 ,engineers endeavor to keep friction losses as low as possible1 and much care is taken in all modern airplane engines to provide adequate methods of lubrication1 or anti-friction bearings at all points where considerable friction exists4 ,,theory ,,of ,,lubrication ,the reason a lubricant is supplied to bearing points will be easily understood if one considers that these elastic substances flow between the close fitting surfaces1 and by filling up the minute depressions in the surfaces and covering the high spots act as a cushion which absorbs the heat generated and takes the wear instead of the metallic bearing surface4 ,the closer the parts fit together the more fluid the lubricant must be to pass between their surfaces1 and at the same time it must possess sufficient body so that it will not be entirely forced out by the pressure existing between the parts4 ,illustration3 ,fig4 #ge4--,showing ,use of ,magnifying ,glass to ,demonstrate that ,apparently ,smooth ,metal ,surfaces ,may ,have ,minute ,irregularities which ,produce ,friction4 ,oils should have good adhesive1 as well as cohesive1 qualities4 ,the former are necessary so that the oil film will cling well to the surfaces of the bearings2 the latter1 so the oil particles will cling together and resist the tendency to separation which exists all the time the bearings are in operation4 ,when used for gas-engine lubrication the oil should be capable of withstanding considerable heat in order that it will not be vaporized by the hot portions of the cylinder4 ,it should have sufficient cold test so that it will remain fluid and flow readily at low temperature4 ,lubricants should be free from acid1 or alkalies1 which tend to produce a chemical action with metals and result in corrosion of the parts to which they are applied4 ,it is imperative that the oil be exactly the proper quality and nature for the purpose intended and that it be applied in a positive manner4 ,the requirements may be briefly summarized as follows3 ,first--,it must have sufficient body to prevent seizing of the parts to which it is applied and between which it is depended upon to maintain an elastic film1 and yet it must not have too much viscosity1 in order to minimize the internal or fluid friction which exists between the particles of the lubricant itself4 ,second--,the lubricant must not coagulate or gum2 must not injure the parts to which it is applied1 either by chemical action or by producing injurious deposits1 and it should not evaporate readily4 ,third--,the character of the work will demand that the oil should not vaporize when heated or thicken to such a point that it will not flow readily when cold4 ,fourth--,the oil must be free from acid1 alkalies1 animal or vegetable fillers1 or other injurious agencies4 ,fifth--,it must be carefully selected for the work required and should be a good conductor of heat4 ,,derivation ,,of ,,lubricants ,the first oils which were used for lubricating machinery were obtained from animal and vegetable sources1 though at the present time most unguents are of mineral derivation4 ,lubricants may exist as fluids1 semifluids1 or solids4 ,the viscosity will vary from light spindle or dynamo oils1 which have but little more body than kerosene1 to the heaviest greases and tallows4 ,the most common solid employed as a lubricant is graphite1 sometimes termed plumbago or black lead4 ,this substance is of mineral derivation4 ,the disadvantage of oils of organic origin1 such as those obtained from animal fats or vegetable substances1 is that they will absorb oxygen from the atmosphere1 which causes them to thicken or become rancid4 ,such oils have a very poor cold test1 as they solidify at comparatively high temperatures1 and their flashing point is so low that they cannot be used at points where much heat exists4 ,in most animal oils various acids are present in greater or less quantities1 and for this reason they are not well adapted for lubricating metallic surfaces which may be raised high enough in temperature to cause decomposition of the oils4 ,lubricants derived from the crude petroleum are called ,oleonaphthas and they are a product of the process of refining petroleum through which gasoline and kerosene are obtained4 ,they are of lower cost than vegetable or animal oil1 and as they are of non-organic origin1 they do not become rancid or gummy by constant exposure to the air1 and they will have no corrosive action on metals because they contain no deleterious substances in chemical composition4 ,by the process of fractional distillation mineral oils of all grades can be obtained4 ,they have a lower cold and higher flash test and there is not the liability of spontaneous combustion that exists with animal oils4 ,the organic oils are derived from fatty substances1 which are present in the bodies of all animals and in some portions of plants4 ,the general method of extracting oil from animal bodies is by a rendering process1 which consists of applying sufficient heat to liquefy the oil and then separating it from the tissue with which it is combined by compression4 ,the only oil which is used to any extent in gas-engine lubrication that is not of mineral derivation is castor oil4 ,this substance has been used on high-speed racing automobile engines and on airplane power plants4 ,it is obtained from the seeds of the castor plant1 which contain a large percentage of oil4 ,among the solid substances which may be used for lubricating purposes may be mentioned tallow1 which is obtained from the fat of animals1 and graphite and soapstone1 which are of mineral derivation4 ,tallow is never used at points where it will be exposed to much heat1 though it is often employed as a filler for greases used in transmission gearing of autos4 ,graphite is sometimes mixed with oil and applied to cylinder lubrication1 though it is most often used in connection with greases in the landing gear parts and for coating wires and cables of the airplane4 ,graphite is not affected by heat1 cold1 acids1 or alkalies1 and has a strong attraction for metal surfaces4 ,it mixes readily with oils and greases and increases their efficiency in many applications4 ,it is sometimes used where it would not be possible to use other lubricants because of extremes of temperature4 ,the oils used for cylinder lubrication are obtained almost exclusively from crude petroleum derived from ,american wells4 ,special care must be taken in the selection of crude material1 as every variety will not yield oil of the proper quality to be used as a cylinder lubricant4 ,the crude petroleum is distilled as rapidly as possible with fire heat to vaporize off the naphthas and the burning oils4 ,after these vapors have been given off superheated steam is provided to assist in distilling4 ,when enough of the light elements have been eliminated the residue is drawn off1 passed through a strainer to free it from grit and earthy matters1 and is afterwards cooled to separate the wax from it4 ,this is the dark cylinder oil and is the grade usually used for steam-engine cylinders4 ,,properties ,,of ,,cylinder ,,oils ,the oil that is to be used in the gasoline engine must be of high quality1 and for that reason the best grades are distilled in a vacuum that the light distillates may be separated at much lower temperatures than ordinary conditions of distilling permit4 ,if the degree of heat is not high the product is not so apt to decompose and deposit carbon4 ,if it is desired to remove the color of the oil which is caused by free carbon and other impurities it can be accomplished by filtering the oil through charcoal4 ,the greater the number of times the oil is filtered1 the lighter it will become in color4 ,the best cylinder oils have flash points usually in excess of #ejj degrees ,f41 and while they have a high degree of viscosity at #ajj degrees ,f4 they become more fluid as the temperature increases4 ,the lubricating oils obtained by refining crude petroleum may be divided into three classes3 ,first--,the natural oils of great body which are prepared for use by allowing the crude material to settle in tanks at high temperature and from which the impurities are removed by natural filtration4 ,these oils are given the necessary body and are free from the volatile substances they contain by means of superheated steam which provides a source of heat4 ,second--,another grade of these natural oils which are filtered again at high temperatures and under pressure through beds of animal charcoal to improve their color4 ,third--,pale1 limpid oils1 obtained by distillation and subsequent chemical treatment from the residuum produced in refining petroleum to obtain the fuel oils4 ,authorities agree that any form of mixed oil in which animal and mineral lubricants are combined should never be used in the cylinder of a gas engine as the admixture of the lubricants does not prevent the decomposition of the organic oil into the glycerides and fatty acids peculiar to the fat used4 ,in a gas-engine cylinder the flame tends to produce more or less charring4 ,the deposits of carbon will be much greater with animal oils than with those derived from the petroleum base because the constituents of a fat or tallow are not of the same volatile character as those which comprise the hydro-carbon oils which will evaporate or volatilize before they char in most instances4 ,,factors ,,influencing ,,lubrication ,,system ,,selection ,the suitability of oil for the proper and efficient lubrication of all internal combustion engines is determined chiefly by the following factors3 #a4 ,type of cooling system 7operating temperatures74 #b4 ,type of lubricating system 7method of applying oil to the moving parts74 #c4 ,rubbing speeds of contact surfaces4 ,were the operating temperatures1 bearing surface speeds and lubrication systems identical1 a single oil could be used in all engines with equal satisfaction4 ,the only change then necessary in viscosity would be that due to climatic conditions4 ,as engines are now designed1 only three grades of oil are necessary for the lubrication of all types with the exception of ,knight1 air-cooled and some engines which run continuously at full load4 ,in the specification of engine lubricants the feature of load carried by the engine should be carefully considered4 ,full ,load ,engines4 #a4 ,marine4 #b4 ,racing automobile4 #c4 ,aviation4 #d4 ,farm tractor4 #e4 ,some stationary4 ,variable ,load ,engines4 #a4 ,pleasure automobile4 #b4 ,commercial vehicle4 #c4 ,motor cycle4 #d4 ,some stationary4 ,of the forms outlined1 the only one we have any immediate concern about is the airplane power plant4 ,the ,platt ,washburn ,refining ,company1 who have made a careful study of the lubrication problem as applied to all types of engines1 have found a peculiar set of conditions to apply to oiling high-speed constant-duty or full-load engines4 ,modern airplane engines are designed to operate continuously at a fairly uniform high rotative speed and at full load over long periods of time4 ,as a sequence to this heavy duty the operating temperatures are elevated4 ,for the sake of extreme lightness in weight of all parts1 very thin alloy steel aluminum or cast iron pistons are fitted and the temperature of the thin piston heads at the center reaches anywhere between #fjj deg4 and #a1djj deg4 ,fahr41 as in automobile racing engines4 ,freely exposed to such intense heat hydro-carbon oils are partially cracked into light and heavy products or polymerized into solid hydro-carbons4 ,from these facts it follows that only heavy mineral oils of low carbon residue and of the greatest chemical purity and stability should be used to secure good lubrication4 ,in all cases the oil should be sufficiently heavy to assure the highest horse-power and fuel and oil economy compatible with perfect lubrication1 avoiding1 at the same time1 carbonization and ignition failure4 ,when aluminum pistons are used their superior heat-conducting properties aid materially in reducing the rate of oil destruction4 ,the extraordinary evolutions described by airplanes in flight make it a matter of vital necessity to operate engines inclined at all angles to the vertical as well as in an upside-down position4 ,to meet this situation lubricating systems have been elaborated so as to deliver an abundance of oil where needed and to eliminate possible flooding of cylinders4 ,this is done by applying a full force feed system1 distributing oil under considerable pressure to all working parts4 ,discharged through the bearings1 the oil drains down to the suction side of a second pump located in the bottom of the base chamber4 ,this pump being of greater capacity than the first prevents the accumulation of oil in the crank-case1 and forces it to a separate oil reservoir-cooler1 whence it flows back in rapid circulation to the pump feeding the bearings4 ,with this arrangement positive lubrication is entirely independent of engine position4 ,the lubricating system of the ,thomas-,morse aviation engines1 which is shown at ,fig4 #gf1 is typical of current practice4 ,illustration3 ,fig4 #gf4--,pressure ,feed ,oiling ,system of ,thomas ,aviation ,engine ,includes ,oil ,cooling ,means4 ,,gnome ,,type ,,engines ,,use ,,castor ,,oil ,the construction and operation of rotative radial cylinder engines introduce additional difficulties of lubrication to those already referred to and merit especial attention4 ,owing to the peculiar alimentation systems of ,gnome type engines1 atomized gasoline mixed with air is drawn through the hollow stationary crank-shaft directly into the crank-case which it fills on the way to the cylinders4 ,therein lies the trouble4 ,hydrocarbon oils are soon dissolved by the gasoline and washed off1 leaving the bearing surfaces without adequate protection and exposed to instant wear and destruction4 ,so castor oil is resorted to as an indispensable but unfortunate compromise4 ,of vegetable origin1 it leaves a much more bulky carbon deposit in the explosion chambers than does mineral oil and its great affinity for oxygen causes the formation of voluminous gummy deposit in the crank-case4 ,engines employing it need to be dismounted and thoroughly scraped out at frequent intervals4 ,it is advisable to use only unblended chemically pure castor oil in rotative engines1 first by virtue of its insolubility in gasoline and second because its extra heavy body can resist the high temperature of air-cooled cylinders4 ,,hall-,,scott ,,lubrication ,,system ,illustration3 ,fig4 #gg4--;,diagram of ,oiling ,system1 ,hall-,scott ,type ,a #abe ,horse-,power ,engine4 ,the oiling system of the ,hall-,scott type ,a-#e #abe horse-power engine is clearly shown at ,fig4 #gg4 ,it is completely described in the instruction book issued by the company from which the following extracts are reproduced by permission4 ,crank-shaft1 connecting rods and all other parts within the crank-case and cylinders are lubricated directly or indirectly by a force-feed oiling system4 ,the cylinder walls and wrist pins are lubricated by oil spray thrown from the lower end of connecting rod bearings4 ,this system is used only upon ,a-#e engines4 ,upon ,a-#g;a and ,a-#e;a engines a small tube supplies oil from connecting rod bearing directly upon the wrist pin4 ,the oil is drawn from the strainer located at the lowest portion of the lower crank-case1 forced around the main intake manifold oil jacket4 ,from here it is circulated to the main distributing pipe located along the lower left hand side of upper crank-case4 ,the oil is then forced directly to the lower side of crank-shaft1 through holes drilled in each main bearing cup4 ,leakage from these main bearings is caught in scuppers placed upon the cheeks of the crank-shafts furnishing oil under pressure to the connecting rod bearings4 ,a-#g;a and ,a-#e;a engines have small tubes leading from these bearings which convey the oil under pressure to the wrist pins4 ,a bi-pass located at the front end of the distributing oil pipe can be regulated to lessen or raise the pressure4 ,by screwing the valve in1 the pressure will raise and more oil will be forced to the bearings4 ,by unscrewing1 pressure is reduced and less oil is fed4 ,a-#g;a and ,a-#e;a engines have oil relief valves located just off of the main oil pump in the lower crank-case4 ,this regulates the pressure at all times so that in cold weather there will be no danger of bursting oil pipes due to excessive pressure4 ,if it is found the oil pressure is not maintained at a high enough level1 inspect this valve4 ,a stronger spring will not allow the oil to bi-pass so freely1 and consequently the pressure will be raised2 a weaker spring will bi-pass more oil and reduce the oil pressure materially4 ,independent of the above-mentioned system1 a small1 directly driven rotary oiler feeds oil to the base of each individual cylinder4 ,the supply of oil is furnished by the main oil pump located in the lower crank-case4 ,a small sight-feed regulator is furnished to control the supply of oil from this oiler4 ,this instrument should be placed higher than the auxiliary oil distributor itself to enable the oil to drain by gravity feed to the oiler4 ,if there is no available place with the necessary height in the front seat of plane1 connect it directly to the intake ,l fitting on the oiler in an upright position4 ,it should be regulated with full open throttle to maintain an oil level in the glass1 approximately half way4 ,an oil pressure gauge is provided4 ,this should be run to the pilot's instrument board4 ,the gauge registers the oil pressure upon the bearings1 also determining its circulation4 ,strict watch should be maintained of this instrument by pilot1 and if for any reason its hand should drop to #j the motor should be immediately stopped and the trouble found before restarting engine4 ,care should be taken that the oil does not work up into the gauge1 as it will prevent the correct gauge registering of oil pressure4 ,the oil pressure will vary according to weather conditions and viscosity of oil used4 ,in normal weather1 with the engine properly warmed up1 the pressure will register on the oil gauge from #e to #aj pounds when the engine is turning from #a1bge to #a1cjj r4 p4 m4 ,this does not apply to all aviation engines1 however1 as the proper pressure advised for the ,curtiss ,,ox-#b motor is from #dj to #ee pounds at the gauge4 ,the oil sump plug is located at the lowest point of the lower crank-case4 ,this is a combination dirt1 water and sediment trap4 ,it is easily removed by unscrewing4 ,oil is furnished mechanically to the cam-shaft housing under pressure through a small tube leading from the main distributing pipe at the propeller end of engine directly into the end of cam-shaft housing4 ,the opposite end of this housing is amply relieved to allow the oil to rapidly flow down upon cam-shaft1 magneto1 pinion-shaft1 and crank-shaft gears1 after which it returns to lower crank-case4 ,an outside overflow pipe is also provided to carry away the surplus oil4 ,,draining ,,oil ,,from ,,crank-,,case ,the oil strainer is placed at the lowest point of the lower crank-case4 ,this strainer should be removed after every five to eight hours running of the engine and cleaned thoroughly with gasoline4 ,it is also advisable to squirt distillate up into the case through the opening where the strainer has been removed4 ,allow this distillate to drain out thoroughly before replacing the plug with strainer attached4 ,be sure gasket is in place on plug before replacing4 ,pour new oil in through either of the two breather pipes on exhaust side of motor4 ,be sure to replace strainer screens if removed4 ,if1 through oversight1 the engine does not receive sufficient lubrication and begins to heat or pound1 it should be stopped immediately4 ,after allowing engine to cool pour at least three gallons of oil into oil sump4 ,fill radiator with water after engine has cooled4 ,should there be apparent damage1 the engine should be thoroughly inspected immediately without further running4 ,if no obvious damage has been done1 the engine should be given a careful examination at the earliest opportunity to see that the running without oil has not burned the bearings or caused other trouble4 ,oils best adapted for ,hall-,scott engines have the following properties3 ,a flash test of not less than #djj deg4 ,f42 viscosity of not less than #ge to #he taken at #ba deg4 ,f4 with ,saybolt's ,universal ,viscosimeter4 ,zeroline heavy duty oil1 manufactured by the ,standard ,oil ,company of ,california2 also1 ,gargoyle mobile ,b oil1 manufactured by the ,vacuum ,oil ,company1 both fulfill the above specifications4 ,one or the other of these oils can be obtained all over the world4 ,monogram extra heavy is also recommended4 ,,oil ,,supply ,,by ,,constant ,,level ,,splash ,,system ,the splash system of lubrication that depends on the connecting rod to distribute the lubricant is one of the most successful and simplest forms for simple four- and six-cylinder vertical automobile engines1 but is not as well adapted to the oiling of airplane power plants for reasons previously stated4 ,if too much oil is supplied the surplus will work past the piston rings and into the combustion chamber1 where it will burn and cause carbon deposits4 ,too much oil will also cause an engine to smoke and an excess of lubricating oil is usually manifested by a bluish-white smoke issuing from the exhaust4 ,a good method of maintaining a constant level of oil for the successful application of the splash system is shown at ,fig4 #gh4 ,the engine base casting includes a separate chamber which serves as an oil container and which is below the level of oil in the crank-case4 ,the lubricant is drawn from the sump or oil container by means of a positive oil pump which discharges directly into the engine case4 ,the level is maintained by an overflow pipe which allows all excess lubricant to flow back into the oil container at the bottom of the cylinder4 ,before passing into the pump again the oil is strained or filtered by a screen of wire gauze and all foreign matter removed4 ,owing to the rapid circulation of the oil it may be used over and over again for quite a period of time4 ,the oil is introduced directly into the crank-case by a breather pipe and the level is indicated by a rod carried by a float which rises when the container is replenished and falls when the available supply diminishes4 ,it will be noted that with such system the only apparatus required besides the oil tank which is cast integral with the bottom of the crank-case is a suitable pump to maintain circulation of oil4 ,this member is always positively driven1 either by means of shaft and universal coupling or direct gearing4 ,as the system is entirely automatic in action1 it will furnish a positive supply of oil at all desired points1 and it cannot be tampered with by the inexpert because no adjustments are provided or needed4 ,,dry ,,crank-,,case ,,system ,,best ,,for ,,airplane ,,engines ,illustration3 ,fig4 #gh4--,sectional ,view of ,typical ,motor ,showing ,parts ,needing ,lubrication and ,method of ,applying ,oil by ,constant ,level ,splash ,system4 ,note also ,water ,jacket and ,spaces for ,water ,circulation4 ,in most airplane power plants it is considered desirable to supply the oil directly to the parts needing it by suitable leads instead of depending solely upon the distributing action of scoops on the connecting rod big ends4 ,a system of this nature is shown at ,fig4 #gg4 ,the oil is carried in the crank-case1 as is common practice1 but the normal oil level is below the point where it will be reached by the connecting rod4 ,it is drawn from the crank-case by a plunger pump which directs it to a manifold leading directly to conductors which supply the main journals4 ,after the oil has been used on these points it drains back into the bottom of the crank-case4 ,an excess is provided which is supplied to the connecting rod ends by passages drilled into the webs of the crank-shaft and part way into the crank-pins as shown by the dotted lines4 ,the oil which is present at the connecting rod crank-pins is thrown off by centrifugal force and lubricates the cylinder walls and other internal parts4 ,regulating screws are provided so that the amount of oil supplied the different points may be regulated at will4 ,a relief check valve is installed to take care of excess lubricant and to allow any oil that does not pass back into the pipe line to overflow or bi-pass into the main container4 ,illustration3 ,fig4 #gi4--,pressure ,feed ,oil-,supply ,system of ,airplane ,power ,plants has ,many ,good ,features4 ,a simple system of this nature is shown graphically in a phantom view of the crank-case at ,fig4 #gi1 in which the oil passages are made specially prominent4 ,the oil is taken from a reservoir at the bottom of the engine base by the usual form of gear oil pump and is supplied to a main feed manifold which extends the length of the crank-case4 ,individual conductors lead to the five main bearings1 which in turn supply the crank-pins by passages drilled through the crank-shaft web4 ,in this power plant the connecting rods are hollow section bronze castings and the passage through the center of the connecting rod serves to convey the lubricant from the crank-pins to the wrist-pins4 ,the cylinder walls are oiled by the spray of lubricant thrown off the revolving crank-shaft by centrifugal force4 ,oil projection by the dippers on the connecting rod ends from constant level troughs is unequal upon the cylinder walls of the two-cylinder blocks of an eight- or twelve-cylinder ,v engine4 ,this gives rise1 on one side of the engine1 to under-lubrication1 and1 on the other side1 to over-lubrication1 as shown at ,fig4 #hj1 ,a4 ,this applies to all modifications of splash lubricating systems4 ,when a force-feed lubricating system is used1 the oil1 escaping past the cheeks of both ends of the crank-pin bearings1 is thrown off at a tangent to the crank-pin circle in all directions1 supplying the cylinders on both sides with an equal quantity of oil1 as at ,fig4 #hj1 ,b4 ,,why ,,cooling ,,systems ,,are ,,necessary ,the reader should understand from preceding chapters that the power of an internal-combustion motor is obtained by the rapid combustion and consequent expansion of some inflammable gas4 ,the operation in brief is that when air or any other gas or vapor is heated1 it will expand and that if this gas is confined in a space which will not permit expansion1 pressure will be exerted against all sides of the containing chamber4 ,the more a gas is heated1 the more pressure it will exert upon the walls of the combustion chamber it confines4 ,pressure in a gas may be created by increasing its temperature and inversely heat may be created by pressure4 ,when a gas is compressed its total volume is reduced and the temperature is augmented4 ,illustration3 ,fig4 #hj4--,why ,pressure ,feed ,system is ,best for ,eight-,cylinder ,vee ,airplane ,engines4 ,the efficiency of any form of heat engine is determined by the power obtained from a certain fuel consumption4 ,a definite amount of energy will be liberated in the form of heat when a pound of any fuel is burned4 ,the efficiency of any heat engine is proportional to the power developed from a definite quantity of fuel with the least loss of thermal units4 ,if the greater proportion of the heat units derived by burning the explosive mixture could be utilized in doing useful work1 the efficiency of the gasoline engine would be greater than that of any other form of energizing power4 ,there is a great loss of heat from various causes1 among which can be cited the reduction of pressure through cooling the motor and the loss of heat through the exhaust valves when the burned gases are expelled from the cylinder4 ,the loss through the water jacket of the average automobile power plant is over #ej per cent4 of the total fuel efficiency4 ,this means that more than half of the heat units available for power are absorbed and dissipated by the cooling water4 ,another #af per cent4 is lost through the exhaust valve1 and but #cc-a_/c per cent4 of the heat units do useful work4 ,the great loss of heat through the cooling systems cannot be avoided1 as some method must be provided to keep the temperature of the engine within proper bounds4 ,it is apparent that the rapid combustion and continued series of explosions would soon heat the metal portions of the engine to a red heat if some means were not taken to conduct much of this heat away4 ,the high temperature of the parts would burn the lubricating oil1 even that of the best quality1 and the piston and rings would expand to such a degree1 especially when deprived of oil1 that they would seize in the cylinder4 ,this would score the walls1 and the friction which ensued would tend to bind the parts so tightly that the piston would stick1 bearings would be burned out1 the valves would warp1 and the engine would soon become inoperative4 ,illustration3 ,fig4 #ha4--,operating ,temperatures of ,automobile ,engine ,parts ,useful as a ,guide to ,understand ,airplane ,power ,plant ,heat4 ,the best temperature to secure efficient operation is one on which considerable difference of opinion exists among engineers4 ,the fact that the efficiency of an engine is dependent upon the ratio of heat converted into useful work compared to that generated by the explosion of the gas is an accepted fact4 ,it is very important that the engine should not get too hot1 and on the other hand it is equally vital that the cylinders be not robbed of too much heat4 ,the object of cylinder cooling is to keep the temperature of the cylinder below the danger point1 but at the same time to have it as high as possible to secure maximum power from the gas burned4 ,the usual operating temperatures of an automobile engine are shown at ,fig4 #ha1 and this can be taken as an approximation of the temperatures apt to exist in an airplane engine of conventional design as well when at ground level or not very high in the air4 ,the newer very high compression airplane engines in which compressions of eight or nine atmospheres are used1 or about #abe pounds per square inch1 will run considerably hotter than the temperatures indicated4 ,,cooling ,,systems ,,generally ,,applied ,there are two general systems of engine cooling in common use1 that in which water is heated by the absorption of heat from the engine and then cooled by air1 and the other method in which the air is directed onto the cylinder and absorbs the heat directly instead of through the medium of water4 ,when the liquid is employed in cooling it is circulated through jackets which surround the cylinder casting and the water may be kept in motion by two methods4 ,the one generally favored is to use a positive circulating pump of some form which is driven by the engine to keep the water in motion4 ,the other system is to utilize a natural principle that heated water is lighter than cold liquid and that it will tend to rise to the top of the cylinder when it becomes heated to the proper temperature and cooled water takes its place at the bottom of the water jacket4 ,air-cooling methods may be by radiation or convection4 ,in the former case the effective outer surface of the cylinder is increased by the addition of flanges machined or cast thereon1 and the air is depended on to rise from the cylinder as heated and be replaced by cooler air4 ,this1 of course1 is found only on stationary engines4 ,when a positive air draught is directed against the cylinder by means of the propeller slip stream in an airplane1 cooling is by convection and radiation both4 ,sometimes the air draught may be directed against the cylinder walls by some form of jacket which confines it to the heated portions of the cylinder4 ,,cooling ,,by ,,positive ,,water ,,circulation ,illustration3 ,fig4 #hb4--,water ,cooling of ,salmson ,seven-,cylinder ,radial ,airplane ,engine4 ,a typical water-cooling system in which a pump is depended upon to promote circulation of the cooling liquid is shown at ,figs4 #hb and #hc4 ,the radiator is carried at the front end of the fuselage in most cases1 and serves as a combined water tank and cooler1 but in some cases it is carried at the side of the engine1 as in ,fig4 #hd1 or attached to the central portion of the aerofoil or wing structure4 ,it is composed of an upper and lower portion joined together by a series of pipes which may be round and provided with a series of fins to radiate the heat1 or which may be flat in order to have the water pass through in thin sheets and cool it more easily4 ,cellular or honeycomb coolers are composed of a large number of bent tubes which will expose a large area of surface to the cooling influence of the air draught forced through the radiator either by the forward movement of the vehicle or by some type of fan4 ,the cellular and flat tube types have almost entirely displaced the flange tube radiators which were formerly popular because they cool the water more effectively1 and may be made lighter than the tubular radiator could be for engines of the same capacity4 ,illustration3 ,fig4 #hc4--;,how ,water ,cooling ,system of ,thomas ,airplane ,engine is ,installed in ,fuselage4 ,the water is drawn from the lower header of the radiator by the pump and is forced through a manifold to the lower portion of the water jackets of the cylinder4 ,it becomes heated as it passes around the cylinder walls and combustion chambers and the hot water passes out of the top of the water jacket to the upper portion of the radiator4 ,here it is divided in thin streams and directed against comparatively cool metal which abstracts the heat from the water4 ,as it becomes cooler it falls to the bottom of the radiator because its weight increases as the temperature becomes lower4 ,by the time it reaches the lower tank of the radiator it has been cooled sufficiently so that it may be again passed around the cylinders of the motor4 ,the popular form of circulating pump is known as the centrifugal type because a rotary impeller of paddle-wheel form throws water which it receives at a central point toward the outside and thus causes it to maintain a definite rate of circulation4 ,the pump is always a separate appliance attached to the engine and driven by positive gearing or direct-shaft connection4 ,the centrifugal pump is not as positive as the gear form1 and some manufacturers prefer the latter because of the positive pumping features4 ,they are very simple in form1 consisting of a suitable cast body in which a pair of spur pinions having large teeth are carried4 ,one of these gears is driven by suitable means1 and as it turns the other member they maintain a flow of water around the pump body4 ,the pump should always be installed in series with the water pipe which conveys the cool liquid from the lower compartment of the radiator to the coolest portion of the water jacket4 ,illustration3 ,fig4 #hd4--;,finned ,tube ,radiators at the ,side of ,hall-,scott ,airplane ,power ,plant ,installed in ,standard ,fuselage4 ,,water ,,circulation ,,by ,,natural ,,system ,some automobile engineers contend that the rapid water circulation obtained by using a pump may cool the cylinders too much1 and that the temperature of the engine may be reduced so much that the efficiency will be lessened4 ,for this reason there is a growing tendency to use the natural method of water circulation as the cooling liquid is supplied to the cylinder jackets just below the boiling point and the water issues from the jacket at the top of the cylinder after it has absorbed sufficient heat to raise it just about to the boiling point4 ,as the water becomes heated by contact with the hot cylinder and combustion-chamber walls it rises to the top of the water jacket1 flows to the cooler1 where enough of the heat is absorbed to cause it to become sensibly greater in weight4 ,as the water becomes cooler1 it falls to the bottom of the radiator and it is again supplied to the water jacket4 ,the circulation is entirely automatic and continues as long as there is a difference in temperature between the liquid in the water spaces of the engine and that in the cooler4 ,the circulation becomes brisker as the engine becomes hotter and thus the temperature of the cylinders is kept more nearly to a fixed point4 ,with the thermosyphon system the cooling liquid is nearly always at its boiling point1 whereas if the circulation is maintained by a pump the engine will become cooler at high speed and will heat up more at low speed4 ,with the thermosyphon1 or natural system of cooling1 more water must be carried than with the pump-maintained circulation methods4 ,the water spaces around the cylinders should be larger1 the inlet and discharge water manifolds should have greater capacity1 and be free from sharp corners which might impede the flow4 ,the radiator must also carry more water than the form used in connection with the pump because of the brisker pump circulation which maintains the engine temperature at a lower point4 ,consideration of the above will show why the pump system is almost universally used in connection with airplane power plant cooling4 ,,direct ,,air-,,cooling ,,methods ,the earliest known method of cooling the cylinder of gas-engines was by means of a current of air passed through a jacket which confined it close to the cylinder walls and was used by ,daimler on his first gas-engine4 ,the gasoline engine of that time was not as efficient as the later form1 and other conditions which materialized made it desirable to cool the engine by water4 ,even as gasoline engines became more and more perfected there has always existed a prejudice against air cooling1 though many forms of engines have been used1 both in automobile and aircraft applications where the air-cooling method has proven to be very practical4 ,the simplest system of air cooling is that in which the cylinders are provided with a series of flanges which increase the effective radiating surface of the cylinder and directing an air-current from a fan against the flanges to absorb the heat4 ,this increase in the available radiating surface of an air-cooled cylinder is necessary because air does not absorb heat as readily as water and therefore more surface must be provided that the excess heat be absorbed sufficiently fast to prevent distortion of the cylinders4 ,air-cooling systems are based on a law formulated by ,newton1 which is3 ,the rate for cooling for a body in a uniform current of air is directly proportional to the speed of the air current and the amount of radiating surface exposed to the cooling effect4 ,,air-,,cooled ,,engine ,,design ,,considerations ,illustration3 ,fig4 #he4--;,anzani ,testing ,his ,five-,cylinder ,air ,cooled ,aviation ,motor ,installed in ,bleriot ,monoplane4 ,note ,exposure of ,flanged ,cylinders to ,propeller ,slip ,stream4 ,there are certain considerations which must be taken into account in designing an air-cooled engine1 which are often overlooked in those forms cooled by water4 ,large valves must be provided to insure rapid expulsion of the flaming exhaust gas and also to admit promptly the fresh cool mixture from the carburetor4 ,the valves of air-cooled engines are usually placed in the cylinder-head1 in order to eliminate any pockets or sharp passages which would impede the flow of gas or retain some of the products of combustion and their heat4 ,when high power is desired multiple-cylinder engines should be used1 as there is a certain limit to the size of a successful air-cooled cylinder4 ,much better results are secured from those having small cubical contents because the heat from small quantities of gas will be more quickly carried off than from greater amounts4 ,all successful engines of the aviation type which have been air-cooled have been of the multiple-cylinder type4 ,an air-cooled engine must be placed in the fuselage1 as at ,fig4 #he1 in such a way that there will be a positive circulation of air around it all the time that it is in operation4 ,the air current may be produced by the tractor screw at the front end of the motor1 or by a suction or blower fan attached to the crank-shaft as in the ,renault engine or by rotating the cylinders as in the ,le ,rhone and ,gnome motors4 ,greater care is required in lubrication of the air-cooled cylinders and only the best quality of oil should be used to insure satisfactory oiling4 ,the combustion chambers must be proportioned so that distribution of metal is as uniform as possible in order to prevent uneven expansion during increase in temperature and uneven contraction when the cylinder is cooled4 ,it is essential that the inside walls of the combustion chamber be as smooth as possible because any sharp angle or projection may absorb sufficient heat to remain incandescent and cause trouble by igniting the mixture before the proper time4 ,the best grades of cast iron or steel should be used in the cylinder and piston and the machine work must be done very accurately so the piston will operate with minimum friction in the cylinder4 ,the cylinder bore should not exceed #d-a_/b or #e inches and the compression pressure should never exceed #ge pounds absolute1 or about five atmospheres1 or serious overheating will result4 ,as an example of the care taken in disposing of the exhaust gases in order to obtain practical air-cooling1 some cylinders are provided with a series of auxiliary exhaust ports uncovered by the piston when it reaches the end of its power stroke4 ,the auxiliary exhaust ports open just as soon as the full force of the explosion has been spent and a portion of the flaming gases is discharged through the ports in the bottom of the cylinder4 ,less of the exhaust gases remains to be discharged through the regular exhaust member in the cylinder-head and this will not heat the walls of the cylinder nearly as much as the larger quantity of hot gas would4 ,that the auxiliary exhaust port is of considerable value is conceded by many designers of fixed and fan-shaped air-cooled motors for airplanes4 ,among the advantages stated for direct air cooling1 the greatest is the elimination of cooling water and its cooling auxiliaries1 which is a factor of some moment1 as it permits considerable reduction in horse-power-weight ratio of the engine1 something very much to be desired4 ,in the temperate zone1 where the majority of airplanes are used1 the weather conditions change in a very few months from the warm summer to the extreme cold winter1 and when water-cooled systems are employed it is necessary to add some chemical substance to the water to prevent it from freezing4 ,the substances commonly employed are glycerine1 wood alcohol1 or a saturated solution of calcium chloride4 ,alcohol has the disadvantage in that it vaporizes readily and must be often renewed4 ,glycerine affects the rubber hose1 while the calcium chloride solution crystallizes and deposits salt in the radiator and water pipes4 ,one of the disadvantages of an air-cooling method1 as stated by those who do not favor this system1 is that engines cooled by air cannot be operated for extended periods under constant load or at very high speed without heating up to such a point that premature ignition of the charge may result4 ,the water-cooling systems1 at the other hand1 maintain the temperature of the engine more nearly constant than is possible with an air-cooled motor1 and an engine cooled by water can be operated under conditions of inferior lubrication or poor mixture adjustment that would seriously interfere with proper and efficient cooling by air4 ,air-cooled motors1 as a rule1 use less fuel than water-cooled engines1 because the higher temperature of the cylinder does not permit of a full charge of gas being inspired on the intake stroke4 ,as special care is needed in operating an air-cooled engine to obtain satisfactory results and because of the greater difficulty which obtains in providing proper lubrication and fuel mixtures which will not produce undue heating1 the air-cooled system has but few adherents at the present time1 and practically all airplanes1 with but very few exceptions1 are provided with water-cooled power plants4 ,those fitted with air-cooled engines are usually short-flight types where maximum lightness is desired in order to obtain high speed and quick climb4 ,the water-cooled engines are best suited for airplanes intended for long flights4 ,the ,gnome1 ,le ,rhone and ,clerget engines are thoroughly practical and have been widely used in ,france and ,england4 ,these are rotary radial cylinder types4 ,the ,anzani is a fixed cylinder engine used on training machines1 while the ,renault is a ,v-type engine made in eight- and twelve-cylinder ,v forms that has been used on reconnaissance and bombing airplanes with success4 ,these types will be fully considered in proper sequence4 ,,chapter ,,viii ,methods of ,cylinder ,construction--,block ,castings--,influence on ,crank-,shaft ,design--,combustion ,chamber ,design--,bore and ,stroke ,ratio--,meaning of ,piston ,speed--,advantage of ,off-,set ,cylinders-- ,valve ,location of ,vital ,import--,valve ,installation ,practice-- ,valve ,design and ,construction--,valve ,operation--,methods of ,driving ,cam-,shaft--,valve ,springs--,valve ,timing--,blowing ,back-- ,lead ,given ,exhaust ,valve--,exhaust ,closing1 ,inlet ,opening-- ,closing the ,inlet ,valve--,time of ,ignition--,how an ,engine ,is ,timed--,gnome ,monosoupape ,valve ,timing--,springless ,valves--,four ,valves per ,cylinder4 ,the improvements noted in the modern internal combustion motors have been due to many conditions4 ,the continual experimenting by leading mechanical minds could have but one ultimate result4 ,the parts of the engines have been lightened and strengthened1 and greater power has been obtained without increasing piston displacement4 ,a careful study has been made of the many conditions which make for efficient motor action1 and that the main principles are well recognized by all engineers is well shown by the standardization of design noted in modern power plants4 ,there are many different methods of applying the same principle1 and it will be the purpose of this chapter to define the ways in which the construction may be changed and still achieve the same results4 ,the various components may exist in many different forms1 and all have their advantages and disadvantages4 ,that all methods are practical is best shown by the large number of successful engines which use radically different designs4 ,,methods ,,of ,,cylinder ,,construction ,one of the most important parts of the gasoline engine and one that has material bearing upon its efficiency is the cylinder unit4 ,the cylinders may be cast individually1 or in pairs1 and it is possible to make all cylinders a unit or block casting4 ,some typical methods of cylinder construction are shown in accompanying illustrations4 ,the appearance of individual cylinder castings may be ascertained by examination of the ,hall-,scott airplane engine4 ,air-cooled engine cylinders are always of the individual pattern4 ,considered from a purely theoretical point of view1 the individual cylinder casting has much in its favor4 ,it is advanced that more uniform cooling is possible than where the cylinders are cast either in pairs or three or four in one casting4 ,more uniform cooling insures that the expansion or change of form due to heating will be more equal4 ,this is an important condition because the cylinder bore must remain true under all conditions of operation4 ,if the heating effect is not uniform1 which condition is liable to obtain if metal is not evenly distributed1 the cylinder may become distorted by heat and the bore be out of truth4 ,when separate cylinders are used it is possible to make a uniform water space and have the cooling liquid evenly distributed around the cylinder4 ,in multiple cylinder castings this is not always the rule1 as in many instances1 especially in four-cylinder block motors where compactness is the main feature1 there is but little space between the cylinders for the passage of water4 ,under such circumstances the cooling effect is not even1 and the stresses which obtain because of unequal expansion may distort the cylinder to some extent4 ,when steel cylinders are made from forgings1 the water jackets are usually of copper or sheet steel attached to the forging by autogenous welding2 in the case of the latter and1 in some cases1 the former may be electro-deposited on the cylinders4 ,,block ,,castings ,illustration3 ,fig4 #hf4--,views of ,four-,cylinder ,duesenberg ,airplane ,engine ,cylinder ,block4 ,the advantage of casting the cylinders in blocks is that a motor may be much shorter than it would be if individual castings were used4 ,it is admitted that when the cylinders are cast together a more compact1 rigid1 and stronger power plant is obtained than when cast separately4 ,there is a disadvantage1 however1 in that if one cylinder becomes damaged it will be necessary to replace the entire unit1 which means scrapping three good cylinders because one of the four has failed4 ,when the cylinders are cast separately one need only replace the one that has become damaged4 ,the casting of four cylinders in one unit is made possible by improved foundry methods1 and when proper provision is made for holding the cores when the metal is poured and the cylinder casts are good1 the construction is one of distinct merit4 ,it is sometimes the case that the proportion of sound castings is less when cylinders are cast in block1 but if the proper precautions are observed in molding and the proper mixtures of cast iron used1 the ratio of defective castings is no more than when cylinders are molded individually4 ,as an example of the courage of engineers in departing from old-established rules1 the cylinder casting shown at ,fig4 #hf may be considered typical4 ,this is used on the ,duesenberg four-cylinder sixteen-valve #d-c_/d x #g engine which has a piston displacement of #dif cu4 in4 ,at a speed of #b1jjj r4p4m41 corresponding to a piston speed of #b1cbe ft4 per min41 the engine is guaranteed to develop #abe horse-power4 ,the weight of the model engine without gear reduction is #dcf lbs41 but a number of refinements have been made in the design whereby it is expected to get the weight down to #cij lbs4 ,the four cylinders are cast from semi-steel in a single block1 with integral heads4 ,the cylinder construction is the same as that which has always been used by ,mr4 ,duesenberg1 inlet and exhaust valves being arranged horizontally opposite each other in the head4 ,there are large openings in the water jacket at both sides and at the ends1 which are closed by means of aluminum covers1 water-tightness being secured by the use of gaskets4 ,this results in a saving in weight because the aluminum covers can be made considerably lighter than it would be possible to cast the jacket walls1 and1 besides1 it permits of obtaining a more nearly uniform thickness of cylinder wall1 as the cores can be much better supported4 ,the cooling water passes completely around each cylinder1 and there is a very considerable space between the two central cylinders1 this being made necessary in order to get the large bearing area desirable for the central bearing4 ,it is common practice to cast the water jackets integral with the cylinders1 if cast iron or aluminum is used1 and this is also the most economical method of applying it because it gives good results in practice4 ,an important detail is that the water spaces must be proportioned so that they are equal around the cylinders whether these members are cast individually1 in pairs1 threes or fours4 ,when cylinders are cast in block form it is good practice to leave a large opening in the jacket wall which will assist in supporting the core and make for uniform water space4 ,it will be noticed that the casting shown at ,fig4 #hf has a large opening in the side of the cylinder block4 ,these openings are closed after the interior of the casting is thoroughly cleaned of all sand1 core wire1 etc41 by brass1 cast iron or aluminum plates4 ,these also have particular value in that they may be removed after the motor has been in use1 thus permitting one to clean out the interior of the water jacket and dispose of the rust1 sediment1 and incrustation which are always present after the engine has been in active service for a time4 ,among the advantages claimed for the practice of casting cylinders in blocks may be mentioned compactness1 lightness1 rigidity1 simplicity of water piping1 as well as permitting the use of simple forms of inlet and exhaust manifolds4 ,the light weight is not only due to the reduction of the cylinder mass but because the block construction permits one to lighten the entire motor4 ,the fact that all cylinders are cast together decreases vibration1 and as the construction is very rigid1 disalignment of working parts is practically eliminated4 ,when inlet and exhaust manifolds are cored in the block casting1 as is sometimes the case1 but one joint is needed on each of these instead of the multiplicity of joints which obtain when the cylinders are individual castings4 ,the water piping is also simplified4 ,in the case of a four-cylinder block motor but two pipes are used2 one for the water to enter the cylinder jacket1 the other for the cooling liquid to discharge through4 ,,influence ,,on ,,crank-,,shaft ,,design ,illustration3 ,fig4 #hg4--,twin-,cylinder ,block of ,sturtevant ,airplane ,engine is ,cast of ,aluminum1 and ,has ,removable ,cylinder ,head4 ,the method of casting the cylinders has a material influence on the design of the crank-shaft as will be shown in proper sequence4 ,when four cylinders are combined in one block it is possible to use a two-bearing crank-shaft4 ,where cylinders are cast in pairs a three-bearing crank-shaft is commonly supplied1 and when cylinders are cast as individual units it is thought necessary to supply a five-bearing crank-shaft1 though sometimes shafts having but three journals are used successfully4 ,obviously the shafts must be stronger and stiffer to withstand the stresses imposed if two supporting bearings are used than if a larger number are employed4 ,in this connection it may be stated that there is less difficulty in securing alignment with a lesser number of bearings and there is also less friction4 ,on the other hand1 the greater the number of points of support a crank-shaft has the lighter the webs can be made and still have requisite strength4 ,,combustion ,,chamber ,,design ,illustration3 ,fig4 #hh4--;,aluminum ,cylinder ,pair ,casting of ,thomas #aej ,horse-,power ,airplane ,engine is of the ,l ,head ,type4 ,another point of importance in the design of the cylinder1 and one which has considerable influence upon the power developed1 is the shape of the combustion chamber4 ,the endeavor of designers is to obtain maximum power from a cylinder of certain proportions1 and the greater energy obtained without increasing piston displacement or fuel consumption the higher the efficiency of the motor4 ,to prevent troubles due to pre-ignition it is necessary that the combustion chamber be made so that there will be no roughness1 sharp corners1 or edges of metal which may remain incandescent when heated or which will serve to collect carbon deposits by providing a point of anchorage4 ,with the object of providing an absolutely clean combustion chamber some makers use a separable head unit to their twin cylinder castings1 such as shown at ,fig4 #hg and ,fig4 #hh4 ,these permit one to machine the entire interior of the cylinder and combustion chamber4 ,the relation of valve location and combustion chamber design will be considered in proper sequence4 ,these cylinders are cast of aluminum1 instead of cast iron1 as is customary1 and are provided with steel or cast iron cylinder liners forced in the soft metal casting bores4 ,,bore ,,and ,,stroke ,,ratio ,a question that has been a vexed one and which has been the subject of considerable controversy is the proper proportion of the bore to the stroke4 ,the early gas engines had a certain well-defined bore to stroke ratio1 as it was usual at that time to make the stroke twice as long as the bore was wide1 but this cannot be done when high speed is desired4 ,with the development of the present-day motor the stroke or piston travel has been gradually shortened so that the relative proportions of bore and stroke have become nearly equal4 ,of late there seems to be a tendency among designers to return to the proportions which formerly obtained1 and the stroke is sometimes one and a half or one and three-quarter times the bore4 ,engines designed for high speed should have the stroke not much longer than the diameter of the bore4 ,the disadvantage of short-stroke engines is that they will not pull well at low speeds1 though they run with great regularity and smoothness at high velocity4 ,the long-stroke engine is much superior for slow speed work1 and it will pull steadily and with increasing power at low speed4 ,it was formerly thought that such engines should never turn more than a moderate number of revolutions1 in order not to exceed the safe piston speed of #a1jjj feet per minute4 ,this old theory or rule of practice has been discarded in designing high efficiency automobile racing and aviation engines1 and piston speeds from #b1ejj to #c1jjj feet per minute are sometimes used1 though the average is around #b1jjj feet per minute4 ,while both short- and long-stroke motors have their advantages1 it would seem desirable to average between the two4 ,that is why a proportion of four to five or six seems to be more general than that of four to seven or eight1 which would be a long-stroke ratio4 ,careful analysis of a number of foreign aviation motors shows that the average stroke is about #a4b times the bore dimensions1 though some instances were noted where it was as high as #a4g times the bore4 ,,meaning ,,of ,,piston ,,speed ,the factor which limits the stroke and makes the speed of rotation so dependent upon the travel of the piston is piston speed4 ,lubrication is the main factor which determines piston speed1 and the higher the rate of piston travel the greater care must be taken to insure proper oiling4 ,let us fully consider what is meant by piston speed4 ,assume that a motor has a piston travel or stroke of six inches1 for the sake of illustration4 ,it would take two strokes of the piston to cover one foot1 or twelve inches1 and as there are two strokes to a revolution it will be seen that this permits of a normal speed of #a1jjj revolutions per minute for an engine with a six-inch stroke1 if one does not exceed #a1jjj feet per minute4 ,if the stroke was only four inches1 a normal speed of #a1ejj revolutions per minute would be possible without exceeding the prescribed limit4 ,the crank-shaft of a small engine1 having three-inch stroke1 could turn at a speed of #b1jjj revolutions per minute without danger of exceeding the safe speed limit4 ,it will be seen that the longer the stroke the slower the speed of the engine1 if one desires to keep the piston speed within the bounds as recommended1 but modern practice allows of greatly exceeding the speeds formerly thought best4 ,,advantages ,,of ,,off-,,set ,,cylinders ,illustration3 ,fig4 #ij4--;,cross ,section of ,austro-,daimler ,engine1 ,showing ,offset ,cylinder ,construction4 ,note ,applied ,water ,jacket and ,peculiar ,valve ,action4 ,another point upon which considerable difference of opinion exists relates to the method of placing the cylinder upon the crank-case--i4e41 whether its center line should be placed directly over the center of the crank-shaft1 or to one side of center4 ,the motor shown at ,fig4 #ij is an off-set type1 in that the center line of the cylinder is a little to one side of the center of the crank-shaft4 ,diagrams are presented at ,fig4 #ia which show the advantages of off-set crank-shaft construction4 ,the view at ,a is a section through a simple motor with the conventional cylinder placing1 the center line of both crank-shaft and cylinder coinciding4 ,the view at ,b shows the cylinder placed to one side of center so that its center line is distinct from that of the crank-shaft and at some distance from it4 ,the amount of off-set allowed is a point of contention1 the usual amount being from fifteen to twenty-five per cent4 of the stroke4 ,the advantages of the off-set are shown at ,fig4 #ia1 ,c4 ,if the crank turns in direction of the arrow there is a certain resistance to motion which is proportional to the amount of energy exerted by the engine and the resistance offered by the load4 ,there are two thrusts acting against the cylinder wall to be considered1 that due to explosion or expansion of the gas1 and that which resists the motion of the piston4 ,these thrusts may be represented by arrows1 one which acts directly in a vertical direction on the piston top1 the other along a straight line through the center of the connecting rod4 ,between these two thrusts one can draw a line representing a resultant force which serves to bring the piston in forcible contact with one side of the cylinder wall1 this being known as side thrust4 ,as shown at ,c1 the crank-shaft is at #ij degrees1 or about one-half stroke1 and the connecting rod is at #bj degrees angle4 ,the shorter connecting rod would increase the diagonal resultant and side thrusts1 while a longer one would reduce the angle of the connecting rod and the side thrust of the piston would be less4 ,with the off-set construction1 as shown at ,d1 it will be noticed that with the same connecting-rod length as shown at ,c and with the crank-shaft at #ij degrees of the circle that the connecting-rod angle is #ad degrees and the side thrust is reduced proportionately4 ,illustration3 ,fig4 #ia4--;,diagrams ,demonstrating ,advantages of ,offset ,crank-,shaft ,construction4 ,another important advantage is that greater efficiency is obtained from the explosion with an off-set crank-shaft1 because the crank is already inclined when the piston is at top center1 and all the energy imparted to the piston by the burning mixture can be exerted directly into producing a useful turning effort4 ,when a cylinder is placed directly on a line with the crank-shaft1 as shown at ,a1 it will be evident that some of the force produced by the expansion of the gas will be exerted in a direct line and until the crank moves the crank throw and connecting rod are practically a solid member4 ,the pressure which might be employed in obtaining useful turning effort is wasted by causing a direct pressure upon the lower half of the main bearing and the upper half of the crank-pin bushing4 ,very good and easily understood illustrations showing advantages of the off-set construction are shown at ,e and ,f4 ,this is a bicycle crank-hanger4 ,it is advanced that the effort of the rider is not as well applied when the crank is at position ,e as when it is at position ,f4 ,position ,e corresponds to the position of the parts when the cylinder is placed directly over the crank-shaft center4 ,position ,f may be compared to the condition which is present when the off-set cylinder construction is used4 ,,valve ,,location ,,of ,,vital ,,import ,it has often been said that a chain is no stronger than its weakest link1 and this is as true of the explosive motor as it is of any other piece of mechanism4 ,many motors which appeared to be excellently designed and which were well constructed did not prove satisfactory because some minor detail or part had not been properly considered by the designer4 ,a factor having material bearing upon the efficiency of the internal combustion motor is the location of the valves and the shape of the combustion chamber which is largely influenced by their placing4 ,the fundamental consideration of valve design is that the gases be admitted and discharged from the cylinder as quickly as possible in order that the speed of gas flow will not be impeded and produce back pressure4 ,this is imperative in obtaining satisfactory operation in any form of motor4 ,if the inlet passages are constricted the cylinder will not fill with explosive mixture promptly1 whereas if the exhaust gases are not fully expelled the parts of the inert products of combustion retained dilute the fresh charge1 making it slow burning and causing lost power and overheating4 ,when an engine employs water as a cooling medium this substance will absorb the surplus heat readily1 and the effects of overheating are not noticed as quickly as when air-cooled cylinders are employed4 ,valve sizes have a decided bearing upon the speed of motors and some valve locations permit the use of larger members than do other positions4 ,while piston velocity is an important factor in determinations of power output1 it must be considered from the aspect of the wear produced upon the various parts of the motor4 ,it is evident that engines which run very fast1 especially of high power1 must be under a greater strain than those operating at lower speeds4 ,the valve-operating mechanism is especially susceptible to the influence of rapid movement1 and the slower the engine the longer the parts will wear and the more reliable the valve action4 ,illustration3 ,fig4 #ib4--;,diagram ,showing ,forms of ,cylinder ,demanded by ,different ,valve ,placings4 ,a--,t ,head ,type1 ,valves on ,opposite ,sides4 ,b--,l ,head ,cylinder1 ,valves ,side by ,side4 ,c--,l ,head ,cylinder1 ,one ,valve in ,head1 ,other in ,pocket4 ,d--,inlet ,valve ,over ,exhaust ,member1 ,both in ,side ,pocket4 ,e--,valve-in-the-,head ,type with ,vertical ,valves4 ,f--,inclined ,valves ,placed to ,open ,directly into ,combustion ,chamber4 ,as will be seen by reference to the accompanying illustration1 ,fig4 #ib1 there are many ways in which valves may be placed in the cylinder4 ,each method outlined possesses some point of advantage1 because all of the types illustrated are used by reputable automobile manufacturers4 ,the method outlined at ,fig4 #ib1 ,a1 is widely used1 and because of its shape the cylinder is known as the ,t form4 ,it is approved for automobile use for several reasons1 the most important being that large valves can be employed and a well-balanced and symmetrical cylinder casting obtained4 ,two independent cam-shafts are needed1 one operating the inlet valves1 the other the exhaust members4 ,the valve-operating mechanism can be very simple in form1 consisting of a plunger actuated by the cam which transmits the cam motion to the valve-stem1 raising the valve as the cam follower rides on the point of the cam4 ,piping may be placed without crowding1 and larger manifolds can be fitted than in some other constructions4 ,this has special value1 as it permits the use of an adequate discharge pipe on the exhaust side with its obvious advantages4 ,this method of cylinder construction is never found on airplane engines because it does not permit of maximum power output4 ,on the other hand1 if considered from a viewpoint of actual heat efficiency1 it is theoretically the worst form of combustion chamber4 ,this disadvantage is probably compensated for by uniformity of expansion of the cylinder because of balanced design4 ,the ignition spark-plug may be located directly over the inlet valve in the path of the incoming fresh gases1 and both valves may be easily removed and inspected by unscrewing the valve caps without taking off the manifolds4 ,the valve installation shown at ,c is somewhat unusual1 though it provides for the use of valves of large diameter4 ,easy charging is insured because of the large inlet valve directly in the top of the cylinder4 ,conditions may be reversed if necessary1 and the gases discharged through this large valve4 ,both methods are used1 though it would seem that the free exhaust provided by allowing the gases to escape directly from the combustion chamber through the overhead valve to the exhaust manifold would make for more power4 ,the method outlined at ,fig4 #ib1 ,f and at ,fig4 #ij is one that has been widely employed on large automobile racing motors where extreme power is required1 as well as in engines constructed for aviation service4 ,the inclination of the valves permits the use of large valves1 and these open directly into the combustion chamber4 ,there are no pockets to retain heat or dead gas1 and free intake and outlet of gas is obtained4 ,this form is quite satisfactory from a theoretical point of view because of the almost ideal combustion chamber form4 ,some difficulty is experienced1 however1 in properly water-jacketing the valve chamber which experience has shown to be necessary if the engine is to have high power4 ,the motor shown at ,fig4 #ib1 ,b and ,fig4 #hh employs cylinders of the ,l type4 ,both valves are placed in a common extension from the combustion chamber1 and being located side by side both are actuated from a common cam-shaft4 ,the inlet and exhaust pipes may be placed on the same side of the engine and a very compact assemblage is obtained1 though this is optional if passages are cored in the cylinder pairs to lead the gases to opposite sides4 ,the valves may be easily removed if desired1 and the construction is fairly good from the viewpoint of both foundry man and machinist4 ,the chief disadvantage is the limited area of the valves and the loss of heat efficiency due to the pocket4 ,this form of combustion chamber1 however1 is more efficient than the ,t head construction1 though with the latter the use of larger valves probably compensates for the greater heat loss4 ,it has been stated as an advantage of this construction that both manifolds can be placed at the same side of the engine and a compact assembly secured4 ,on the other hand1 the disadvantage may be cited that in order to put both pipes on the same side they must be of smaller size than can be used when the valves are oppositely placed4 ,the ,l form cylinder is sometimes made more efficient if but one valve is placed in the pocket while the other is placed over it4 ,this construction is well shown at ,fig4 #ib1 ,d and is found on ,anzani motors4 ,illustration3 ,fig4 #ic4--,sectional ,view of ,engine ,cylinder ,showing ,valve and ,cage ,installation4 ,the method of valve application shown at ,fig4 #hg is an ingenious method of overcoming some of the disadvantages inherent with valve-in-the-head motors4 ,in the first place it is possible to water-jacket the valves thoroughly1 which is difficult to accomplish when they are mounted in cages4 ,the water circulates directly around the walls of the valve chambers1 which is superior to a construction where separate cages are used1 as there are two thicknesses of metal with the latter1 that of the valve-cage proper and the wall of the cylinder4 ,the cooling medium is in contact only with the outer wall1 and as there is always a loss of heat conductivity at a joint it is practically impossible to keep the exhaust valves and their seats at a uniform temperature4 ,the valves may be of larger size without the use of pockets when seating directly in the head4 ,in fact1 they could be equal in diameter to almost half the bore of the cylinder1 which provides an ideal condition of charge placement and exhaust4 ,when valve grinding is necessary the entire head is easily removed by taking off six nuts and loosening inlet manifold connections1 which operation would be necessary even if cages were employed1 as in the engine shown at ,fig4 #ic4 ,illustration3 ,fig4 #id4--;,diagrams ,showing ,how ,gas ,enters ,cylinder ,through ,overhead ,valves and ,other ,types4 ,a--,tee ,head ,cylinder4 ,b--,l ,head ,cylinder4 ,c--,overhead ,valve4 ,illustration3 ,fig4 #ie4--;,conventional ,methods of ,operating ,internal ,combustion ,motor ,valves4 ,at ,fig4 #id1 ,a and ,b1 a section through a typical ,l-shaped cylinder is depicted4 ,it will be evident that where a pocket construction is employed1 in addition to its faculty for absorbing heat1 the passage of gas would be impeded4 ,for example1 the inlet gas rushing in through the open valve would impinge sharply upon the valve-cap or combustion head directly over the valve and then must turn at a sharp angle to enter the combustion chamber and then at another sharp angle to fill the cylinders4 ,the same conditions apply to the exhaust gases1 though they are reversed4 ,when the valve-in-the-head type of cylinder is employed1 as at ,c1 the only resistance offered the gas is in the manifold4 ,as far as the passage of the gases in and out of the cylinder is concerned1 ideal conditions obtain4 ,it is claimed that valve-in-the-head motors are more flexible and responsive than other forms1 but the construction has the disadvantage in that the valves must be opened through a rather complicated system of push rods and rocker arms instead of the simpler and direct plunger which can be used with either the ,t or ,l head cylinders4 ,this is clearly outlined in the illustrations at ,fig4 #ie1 where ,a shows the valve in the head-operating mechanism necessary if the cam-shaft is carried at the cylinder base1 while ,b shows the most direct push-rod action obtained with ,t or ,l head cylinder placing4 ,illustration3 ,fig4 #if4--;,examples of ,direct ,valve ,actuation by ,overhead ,cam-,shaft4 ,a--,mercedes4 ,b--,hall-,scott4 ,c--,wisconsin4 ,illustration3 ,fig4 #ig4 ,,censored ,illustration3 ,fig4 #ih4 ,,censored ,the objection can be easily met by carrying the cam-shaft above the cylinders and driving it by means of gearing4 ,the types of engine cylinders using this construction are shown at ,fig4 #if1 and it will be evident that a positive and direct valve action is possible by following the construction originated by the ,mercedes 7,german7 aviation engine designers and outlined at ,a4 ,the other forms at ,b and ,c are very clearly adaptations of this design4 ,the ,hall-,scott engine at ,fig4 #ig is depicted in part section and no trouble will be experienced in understanding the bevel pinion and gear drive from the crank-shaft to the overhead cam-shaft through a vertical counter-shaft4 ,a very direct valve action is used in the ,duesenberg engines1 one of which is shown in part section at ,fig4 #ih4 ,the valves are parallel with the piston top and are actuated by rocker arms1 one end of which bears against the valve stem1 and the other rides the cam-shaft4 ,illustration3 ,fig4 #ii4--,sectional ,views ,showing ,arrangement of ,novel ,concentric ,valve ,arrangement ,devised by ,panhard for ,aerial ,engines4 ,the form shown at ,fig4 #ii shows an ingenious application of the valve-in-the-head idea which permits one to obtain large valves4 ,it has been used on some of the ,panhard aviation engines and on the ,american ,aeromarine power plants4 ,the inlet passage is controlled by the sliding sleeve which is hollow and slotted so as to permit the inlet gases to enter the cylinder through the regular type poppet valve which seats in the exhaust sleeve4 ,when the exhaust valve is operated by the tappet rod and rocker arm the intake valve is also carried down with it4 ,the intake gas passage is closed1 however1 and the burned gases are discharged through the large annular passage surrounding the sleeve4 ,when the inlet valve leaves its seat in the sleeve the passage of cool gas around the sleeve keeps the temperature of both valves to a low point and the danger of warping is minimized4 ,a dome-shaped combustion chamber may be used1 which is an ideal form in conserving heat efficiency1 and as large valves may be installed the flow of both fresh and exhaust gases may be obtained with minimum resistance4 ,the intake valve is opened by a small auxiliary rocker arm which is lifted when the cam follower rides into the depression in the cam by the action of the strong spring around the push rod4 ,when the cam follower rides on the high point the exhaust sleeve is depressed from its seat against the cylinder4 ,by using a cam having both positive and negative profiles1 a single rod suffices for both valves because of its push and pull action4 ,,valve ,,design ,,and ,,construction ,valve dimensions are an important detail to be considered and can be determined by several conditions1 among which may be cited method of installation1 operating mechanism1 material employed1 engine speed desired1 manner of cylinder cooling and degree of lift desired4 ,a review of various methods of valve location has shown that when the valves are placed directly in the head we can obtain the ideal cylinder form1 though larger valves may be used if housed in a separate pocket1 as afforded by the ,t head construction4 ,the method of operation has much to do with the size of the valves4 ,for example1 if an automatic inlet valve is employed it is good practice to limit the lift and obtain the required area of port opening by augmenting the diameter4 ,because of this a valve of the automatic type is usually made twenty per cent4 larger than one mechanically operated4 ,when both are actuated by cam mechanism1 as is now common practice1 they are usually made the same size and are interchangeable1 which greatly simplifies manufacture4 ,the relation of valve diameter to cylinder bore is one that has been discussed for some time by engineers4 ,the writer's experience would indicate that they should be at least half the bore1 if possible4 ,while the mushroom type or poppet valve has become standard and is the most widely used form at the present time1 there is some difference of opinion among designers as to the materials employed and the angle of the seat4 ,most valves have a bevel seat1 though some have a flat seating4 ,the flat seat valve has the distinctive advantage of providing a clear opening with lesser lift1 this conducing to free gas flow4 ,it also has value because it is silent in operation1 but the disadvantage is present that best material and workmanship must be used in their construction to obtain satisfactory results4 ,as it can be made very light it is particularly well adapted for use as an automatic inlet valve4 ,among other disadvantages cited is the claim that it is more susceptible to derangement1 owing to the particles of foreign matter getting under the seat4 ,with a bevel seat it is argued that the foreign matter would be more easily dislodged by the gas flow1 and that the valve would close tighter because it is drawn positively against the bevel seat4 ,several methods of valve construction are the vogue1 the most popular form being the one-piece type2 those which are composed of a head of one material and stem of another are seldom used in airplane engines because they are not reliable4 ,in the built-up construction the head is usually of high nickel steel or cast iron1 which metals possess good heat-resisting qualities4 ,heads made of these materials are not likely to warp1 scale1 or pit1 as is sometimes the case when ordinary grades of machinery steel are used4 ,the cast-iron head construction is not popular because it is often difficult to keep the head tight on the stem4 ,there is a slight difference in expansion ratio between the head and the stem1 and as the stem is either screwed or riveted to the cast-iron head the constant hammering of the valve against its seat may loosen the joint4 ,as soon as the head is loose on the stem the action of the valve becomes erratic4 ,the best practice is to machine the valves from tungsten steel forgings4 ,this material has splendid heat-resisting qualities and will not pit or become scored easily4 ,even the electrically welded head to stem types which are used in automobile engines are not looked upon with favor in the aviation engine4 ,valve stem guides and valve stems must be machined very accurately to insure correct action4 ,the usual practice in automobile engines is shown at ,fig4 #ajj4 ,illustration3 ,fig4 #ajj4--,showing ,clearance ,allowed ,between ,valve ,stem and ,valve ,stem ,guide to ,secure ,free ,action4 ,,valve ,,operation ,the methods of valve operation commonly used vary according to the type of cylinder construction employed4 ,in all cases the valves are lifted from their seats by cam-actuated mechanism4 ,various forms of valve-lifting cams are shown at ,fig4 #aja4 ,as will be seen1 a cam consists of a circle to which a raised1 approximately triangular member has been added at one point4 ,when the cam follower rides on the circle1 as shown at ,fig4 #ajb1 there is no difference in height between the cam center and its periphery and there is no movement of the plunger4 ,as soon as the raised portion of the cam strikes the plunger it will lift it1 and this reciprocating movement is transmitted to the valve stem by suitable mechanical connections4 ,illustration3 ,fig4 #aja4--;,forms of ,valve-,lifting ,cams ,generally ,employed4 ,a--,cam ,profile for ,long ,dwell and ,quick ,lift4 ,b--,typical ,inlet ,cam ,used with ,mushroom ,type ,follower4 ,c--,average ,form of ,cam4 ,d--,designed to ,give ,quick ,lift and ,gradual ,closing4 ,the cam forms outlined at ,fig4 #aja are those commonly used4 ,that at ,a is used on engines where it is desired to obtain a quick lift and to keep the valve fully opened as long as possible4 ,it is a noisy form1 however1 and is not very widely employed4 ,that at ,b is utilized more often as an inlet cam while the profile shown at ,c is generally depended on to operate exhaust valves4 ,the cam shown at ,d is a composite form which has some of the features of the other three types4 ,it will give the quick opening of form ,a1 the gradual closing of form ,b1 and the time of maximum valve opening provided by cam profile ,c4 ,illustration3 ,fig4 #ajb4--,showing ,principal ,types of ,cam ,followers which ,have ,received ,general ,application4 ,the various types of valve plungers used are shown at ,fig4 #ajb4 ,that shown at ,a is the simplest form1 consisting of a simple cylindrical member having a rounded end which follows the cam profile4 ,these are sometimes made of square stock or kept from rotating by means of a key or pin4 ,a line contact is possible when the plunger is kept from turning1 whereas but a single point bearing is obtained when the plunger is cylindrical and free to revolve4 ,the plunger shown at ,a will follow only cam profiles which have gradual lifts4 ,the plunger shown at ,b is left free to revolve in the guide bushing and is provided with a flat mushroom head which serves as a cam follower4 ,the type shown at ,c carries a roller at its lower end and may follow very irregular cam profiles if abrupt lifts are desired4 ,while forms ,a and ,b are the simplest1 that outlined at ,c in its various forms is more widely used4 ,compound plungers are used on the ,curtiss ,,ox-#b motors1 one inside the other4 ,the small or inner one works on a cam of conventional design1 the outer plunger follows a profile having a flat spot to permit of a pull rod action instead of a push rod action4 ,all the methods in which levers are used to operate valves are more or less noisy because clearance must be left between the valve stem and the stop of the plunger4 ,the space must be taken up before the valve will leave its seat1 and when the engine is operated at high speeds the forcible contact between the plunger and valve stem produces a rattling sound until the valves become heated and expand and the stems lengthen out4 ,clearance must be left between the valve stems and actuating means4 ,this clearance is clearly shown in ,fig4 #ajc and should be 4#jbj 7twenty thousandths7 when engine is cold4 ,the amount of clearance allowed depends entirely upon the design of the engine and length of valve stem4 ,on the ,curtiss ,,ox-#b engines the clearance is but 4#jaj 7ten thousandths7 because the valve stems are shorter4 ,too little clearance will result in loss of power or misfiring when engine is hot4 ,too much clearance will not allow the valve to open its full amount and will disturb the timing4 ,illustration3 ,fig4 #ajc4--;,diagram ,showing ,proper ,clearance to ,allow ,between ,adjusting ,screw and ,valve ,stems in ,hall-,scott ,aviation ,engines4 ,,methods ,,of ,,driving ,,cam-,,shaft ,two systems of cam-shaft operation are used4 ,the most common of these is by means of gearing of some form4 ,if the cam-shaft is at right angles to the crank-shaft it may be driven by worm1 spiral1 or bevel gearing4 ,if the cam-shaft is parallel to the crank-shaft1 simple spur gear or chain connection may be used to turn it4 ,a typical cam-shaft for an eight-cylinder ,v engine is shown at ,fig4 #ajd4 ,it will be seen that the sixteen cams are forged integrally with the shaft and that it is spur-gear driven4 ,the cam-shaft drive of the ,hall-,scott motor is shown at ,fig4 #ig4 ,illustration3 ,fig4 #ajd4--;,cam-,shaft of ,thomas ,airplane ,motor ,has ,cams ,forged ,integral4 ,note ,split ,cam-,shaft ,bearings and ,method of ,gear ,retention4 ,while gearing is more commonly used1 considerable attention has been directed of late to silent chains for cam-shaft operation4 ,the ordinary forms of block or roller chain have not proven successful in this application1 but the silent chain1 which is in reality a link belt operating over toothed pulleys1 has demonstrated its worth4 ,the tendency to its use is more noted on foreign motors than those of ,american design4 ,it first came to public notice when employed on the ,daimler-,knight engine for driving the small auxiliary crank-shafts which reciprocated the sleeve valves4 ,the advantages cited for the application of chains are1 first1 silent operation1 which obtains even after the chains have worn considerably2 second1 in designing it is not necessary to figure on maintaining certain absolute center distances between the crank-shaft and cam-shaft sprockets1 as would be the case if conventional forms of gearing were used4 ,on some forms of motor employing gears1 three and even four members are needed to turn the cam-shaft4 ,with a chain drive but two sprockets are necessary1 the chain forming a flexible connection which permits the driving and driven members to be placed at any distance apart that the exigencies of the design demand4 ,when chains are used it is advised that some means for compensating chain slack be provided1 or the valve timing will lag when chains are worn4 ,many combination drives may be worked out with chains that would not be possible with other forms of gearing4 ,direct gear drive is favored at the present time by airplane engine designers because they are the most certain and positive means1 even when a number of gears must be used as intermediate drive members4 ,with overhead cam-shafts1 bevel gears work out very well in practice1 as in the ,hall-,scott motors and others of that type4 ,,valve ,,springs ,illustration3 ,fig4 #aje4--,section ,through ,cylinder of ,knight ,motor1 ,showing ,important ,parts of ,valve ,motion4 ,another consideration of importance is the use of proper valve-springs1 and particular care should be taken with those1 of automatic valves4 ,the spring must be weak enough to allow the valve to open when the suction is light1 and must be of sufficient strength to close it in time at high speeds4 ,it should be made as large as possible in diameter and with a large number of convolutions1 in order that fatigue of the metal be obviated1 and it is imperative that all springs be of the same strength when used on a multiple-cylinder engine4 ,practically all valves used to control the gas flow in airplane engines are mechanically operated4 ,on the exhaust valve the spring must be strong enough so that the valve will not be sucked in on the inlet stroke4 ,it should be borne in mind that if the spring is too strong a strain will be imposed on the valve-operating mechanism1 and a hammering action produced which may cause deformation of the valve-seat4 ,only pressure enough to insure that the operating mechanism will follow the cam is required4 ,it is common practice to make the inlet and exhaust valve springs of the same tension when the valves are of the same size and both mechanically operated4 ,this is done merely to simplify manufacture and not because it is necessary for the inlet valve-spring to be as strong as the other4 ,valve springs of the helical coil type are generally used1 though torsion or scissors springs and laminated or single-leaf springs are also utilized in special applications4 ,two springs are used on each valve in some valve-in-the-head types2 a spring of small pitch diameter inside the regular valve-spring and concentric with it4 ,its function is to keep the valve from falling into the cylinder in event of breakage of the main spring in some cases1 and to provide a stronger return action in others4 ,illustration3 ,fig4 #ajf4--;,diagrams ,showing ,knight ,sleeve ,valve ,action4 ,,knight ,,slide ,,valve ,,motor ,the sectional view through the cylinder at ,fig4 #aje shows the ,knight sliding sleeves and their actuating means very clearly4 ,the diagrams at ,fig4 #ajf show graphically the sleeve movements and their relation to the crank-shaft and piston travel4 ,the action may be summed up as follows3 ,the inlet port begins to open when the lower edge of the opening of the outside sleeve which is moving down passes the top of the slot in the inner member also moving downwardly4 ,the inlet port is closed when the lower edge of the slot in the inner sleeve which is moving up passes the top edge of the port in the outer sleeve which is also moving toward the top of the cylinder4 ,the inlet opening extends over two hundred degrees of crank motion4 ,the exhaust port is uncovered slightly when the lower edge of the port in the inner sleeve which is moving down passes the lower edge of the portion of the cylinder head which protrudes in the cylinder4 ,when the top of the port in the outer sleeve traveling toward the bottom of the cylinder passes the lower edge of the slot in the cylinder wall the exhaust passage is closed4 ,the exhaust opening extends over a period corresponding to about two hundred and forty degrees of crank motion4 ,the ,knight motor has not been applied to aircraft to the writer's knowledge1 but an eight-cylinder ,vee design that might be useful in that connection if lightened is shown at ,fig4 #ajg4 ,the main object is to show that the ,knight valve action is the only other besides the mushroom or poppet valve that has been applied successfully to high speed gasoline engines4 ,,valve ,,timing ,it is in valve timing that the greatest difference of opinion prevails among engineers1 and it is rare that one will see the same formula in different motors4 ,it is true that the same timing could not be used with motors of different construction1 as there are many factors which determine the amount of lead to be given to the valves4 ,the most important of these is the relative size of the valve to the cylinder bore1 the speed of rotation it is desired to obtain1 the fuel efficiency1 the location of the valves1 and other factors too numerous to mention4 ,illustration3 ,fig4 #ajg4--;,cross ,sectional ,view of ,knight ,type ,eight ,cylinder ,v ,engine4 ,most of the readers should be familiar with the cycle of operation of the internal combustion motor of the four-stroke type1 and it seems unnecessary to go into detail except to present a review4 ,the first stroke of the piston is one in which a charge of gas is taken into the motor2 the second stroke1 which is in reverse direction to the first1 is a compression stroke1 at the end of which the spark takes place1 exploding the charge and driving the piston down on the third or expansion stroke1 which is in the same direction as the intake stroke1 and finally1 after the piston has nearly reached the end of this stroke1 another valve opens to allow the burned gases to escape1 and remains open until the piston has reached the end of the fourth stroke and is in a position to begin the series over again4 ,the ends of the strokes are reached when the piston comes to a stop at either top or bottom of the cylinder and reverses its motion4 ,that point is known as a center1 and there are two for each cylinder1 top and bottom centers1 respectively4 ,all circles may be divided into #cfj parts1 each of which is known as a degree1 and1 in turn1 each of these degrees may be again divided into minutes and seconds1 though we need not concern ourselves with anything less than the degree4 ,each stroke of the piston represents #ahj degrees travel of the crank1 because two strokes represent one complete revolution of three hundred and sixty degrees4 ,the top and bottom centers are therefore separated by #ahj degrees4 ,theoretically each phase of a four-cycle engine begins and ends at a center1 though in actual practice the inertia or movement of the gases makes it necessary to allow a lead or lag to the valve1 as the case may be4 ,if a valve opens before a center1 the distance is called lead2 if it closes after a center1 this distance is known as lag4 ,the profile of the cams ordinarily used to open or close the valves represents a considerable time in relation to the #ahj degrees of the crank-shaft travel1 and the area of the passages through which the gases are admitted or exhausted is quite small owing to the necessity of having to open or close the valves at stated times2 therefore1 to open an adequately large passage for the gases it is necessary to open the valves earlier and close them later than at centers4 ,that advancing the opening of the exhaust valve was of value was discovered on the early motors and is explained by the necessity of releasing a large amount of gas1 the volume of which has been greatly raised by the heat of combustion4 ,when the inlet valves were mechanically operated it was found that allowing them to lag at closing enabled the inspiration of a greater volume of gas4 ,disregarding the inertia or flow of the gases1 opening the exhaust at center would enable one to obtain full value of the expanding gases the entire length of the piston stroke1 and it would not be necessary to keep the valve open after the top center1 as the reverse stroke would produce a suction effect which might draw some of the inert charge back into the cylinder4 ,on the other hand1 giving full consideration to the inertia of the gas1 opening the valve before center is reached will provide for quick expulsion of the gases1 which have sufficient velocity at the end of the stroke1 so that if the valve is allowed to remain open a little longer1 the amount of lag varying with the opinions of the designer1 the cylinder is cleared in a more thorough manner4 ,,blowing ,,back ,when the factor of retarded opening is considered without reckoning the inertia of the gases1 it would appear that if the valve were allowed to remain open after center had passed1 say1 on the closing of the inlet1 the piston1 having reversed its motion1 would have the effect of expelling part of the fresh charge through the still open valve as it passed inward at its compression stroke4 ,this effect is called blowing back1 and is often noted with motors where the valve settings are not absolutely correct1 or where the valve-springs or seats are defective and prevent proper closing4 ,this factor is not of as much import as might appear1 as on closer consideration it will be seen that the movement of the piston as the crank reaches either end of the stroke is less per degree of angular movement than it is when the angle of the connecting rod is greater4 ,then1 again1 a certain length of time is required for the reversal of motion of the piston1 during which time the crank is in motion but the piston practically at a standstill4 ,if the valves are allowed to remain open during this period1 the passage of the gas in or out of the cylinder will be by its own momentum4 ,,lead ,,given ,,exhaust ,,valve ,the faster a motor turns1 all other things being equal1 the greater the amount of lead or advance it is necessary to give the opening of the exhaust valve4 ,it is self-evident truth that if the speed of a motor is doubled it travels twice as many degrees in the time necessary to lower the pressure4 ,as most designers are cognizant of this fact1 the valves are proportioned accordingly4 ,it is well to consider in this respect that the cam profile has much to do with the manner in which the valve is opened2 that is1 the lift may be abrupt and the gas allowed to escape in a body1 or the opening may be gradual1 the gas issuing from the cylinder in thin streams4 ,an analogy may be made with the opening of any bottle which contains liquid highly carbonated4 ,if the cork is removed suddenly the gas escapes with a loud pop1 but1 on the other hand1 if the bottle is uncorked gradually1 the gas escapes from the receptacle in thin streams around the cork1 and passage of the gases to the air is accomplished without noise4 ,while the second plan is not harsh1 it is slower than the former1 as must be evident4 ,,exhaust ,,closing1 ,,inlet ,,opening ,a point which has been much discussed by engineers is the proper relation of the closing of the exhaust valve and the opening of the inlet4 ,theoretically they should succeed each other1 the exhaust closing at upper dead center and the inlet opening immediately afterward4 ,the reason why a certain amount of lag is given the exhaust closing in practice is that the piston cannot drive the gases out of the cylinder unless they are compressed to a degree in excess of that existing in the manifold or passages1 and while toward the end of the stroke this pressure may be feeble1 it is nevertheless indispensable4 ,at the end of the piston's stroke1 as marked by the upper dead center1 this compression still exists1 no matter how little it may be1 so that if the exhaust valve is closed and the inlet opened immediately afterward1 the pressure which exists in the cylinder may retard the entrance of the fresh gas and a certain portion of the inert gas may penetrate into the manifold4 ,as the piston immediately begins to aspirate1 this may not be serious1 but as these gases are drawn back into the cylinder the fresh charge will be diluted and weakened in value4 ,if the spark-plug is in a pocket1 the points may be surrounded by this weak gas1 and the explosion will not be nearly as energetic as when the ignition spark takes place in pure mixture4 ,it is a well-known fact that the exhaust valve should close after dead center and that a certain amount of lag should be given to opening of the inlet4 ,the lag given the closing of the exhaust valve should not be as great as that given the closing of the inlet valve4 ,assuming that the excess pressure of the exhaust will equal the depression during aspiration1 the time necessary to complete the emptying of the cylinder will be proportional to the volume of the gas within it4 ,at the end of the suction stroke the volume of gas contained in the cylinder is equal to the cylindrical volume plus the space of the combustion chamber4 ,at the end of the exhaust stroke the volume is but that of the dead space1 and from one-third to one-fifth its volume before compression4 ,while it is natural to assume that this excess of burned gas will escape faster than the fresh gas will enter the cylinder1 it will be seen that if the inlet valve were allowed to lag twenty degrees1 the exhaust valve lag need not be more than five degrees1 providing that the capacity of the combustion chamber was such that the gases occupied one-quarter of their former volume4 ,it is evident that no absolute rule can be given1 as back pressure will vary with the design of the valve passages1 the manifolds1 and the construction of the muffler4 ,the more direct the opening1 the sooner the valve can be closed and the better the cylinder cleared4 ,ten degrees represent an appreciable angle of the crank1 and the time required for the crank to cover this angular motion is not inconsiderable and an important quantity of the exhaust may escape1 but the piston is very close to the dead center after the distance has been covered4 ,before the inlet valve opens there should be a certain depression in the cylinder1 and considerable lag may be allowed before the depression is appreciable4 ,so far as the volume of fresh gas introduced during the admission stroke is concerned1 this is determined by the displacement of the piston between the point where the inlet valve opens and the point of closing1 assuming that sufficient gas has been inspired so that an equilibrium of pressure has been established between the interior of the cylinder and the outer air4 ,the point of inlet opening varies with different motors4 ,it would appear that a fair amount of lag would be fifteen degrees past top center for the inlet opening1 as a certain depression will exist in the cylinder1 assuming that the exhaust valve has closed five or ten degrees after center1 and at the same time the piston has not gone down far enough on its stroke to materially decrease the amount of gas which will be taken into the cylinder4 ,,closing ,,the ,,inlet ,,valve ,as in the case with the other points of opening and closing1 there is a wide diversity of practice as relates to closing the inlet valve4 ,some of the designers close this exactly at bottom center1 but this practice cannot be commended1 as there is a considerable portion of time1 at least ten or fifteen degrees angular motion of the crank1 before the piston will commence to travel to any extent on its compression stroke4 ,the gases rushing into the cylinder have considerable velocity1 and unless an equilibrium is obtained between the pressure inside and that of the atmosphere outside1 they will continue to rush into the cylinder even after the piston ceases to exert any suction effect4 ,for this reason1 if the valve is closed exactly on center1 a full charge may not be inspired into the cylinder1 though if the time of closing is delayed1 this momentum or inertia of the gas will be enough to insure that a maximum charge is taken into the cylinder4 ,the writer considers that nothing will be gained if the valve is allowed to remain open longer than twenty degrees1 and an analysis of practice in this respect would seem to confirm this opinion4 ,from that point in the crank movement the piston travel increases and the compressive effect is appreciable1 and it would appear that a considerable proportion of the charge might be exhausted into the manifold and carburetor if the valve were allowed to remain open beyond a point corresponding to twenty degrees angular movement of the crank4 ,,time ,,of ,,ignition ,in this country engineers unite in providing a variable time of ignition1 though abroad some difference of opinion is noted on this point4 ,the practice of advancing the time of ignition1 when affected electrically1 was severely condemned by early makers1 these maintaining that it was necessary because of insufficient heat and volume of the spark1 and it was thought that advancing ignition was injurious4 ,the engineers of to-day appreciate the fact that the heat of the electric spark1 especially when from a mechanical generator of electrical energy1 is the only means by which we can obtain practically instantaneous explosion1 as required by the operation of motors at high speeds1 and for the combustion of large volumes of gas4 ,illustration3 ,fig4 #ajh4--;,diagrams ,explaining ,valve and ,ignition ,timing of ,hall-,scott ,aviation ,engine4 ,it is apparent that a motor with a fixed point of ignition is not as desirable1 in every way1 as one in which the ignition can be advanced to best meet different requirements1 and the writer does not readily perceive any advantage outside of simplicity of control in establishing a fixed point of ignition4 ,in fact1 there seems to be some difference of opinion among those designers who favor fixed ignition1 and in one case this is located forty-three degrees ahead of center1 and in another motor the point is fixed at twenty degrees1 so that it may be said that this will vary as much as one hundred per cent4 in various forms4 ,this point will vary with different methods of ignition1 as well as the location of the spark-plug or igniter4 ,for the sake of simplicity1 most airplane engines use set spark2 if an advancing and retarding mechanism is fitted1 it is only to facilitate starting1 as the spark is kept advanced while in flight1 and control is by throttle alone4 ,illustration3 ,fig4 #aji4--,timing ,diagram of ,typical ,six-,cylinder ,engine4 ,it is obvious by consideration of the foregoing that there can be no arbitrary rules established for timing1 because of the many conditions which determine the best times for opening and closing the valves4 ,it is customary to try various settings when a new motor is designed until the most satisfactory points are determined1 and the setting which will be very suitable for one motor is not always right for one of different design4 ,the timing diagram shown at ,fig4 #ajh applies to the ,hall-,scott engine1 and may be considered typical4 ,it should be easily followed in view of the very complete explanation given in preceding pages4 ,another six-cylinder engine diagram is shown at ,fig4 #aji1 and an eight-cylinder timing diagram is shown at ,fig4 #aaj4 ,in timing automobile engines no trouble is experienced1 because timing marks are always indicated on the engine fly-wheel register with an indicating trammel on the crank-case4 ,to time an airplane engine accurately1 as is necessary to test for a suspected cam-shaft defect1 a timing disc of aluminum is attached to the crank-shaft which has the timing marks indicated thereon4 ,if the disc is made #aj or #ab inches in diameter1 it may be divided into degrees without difficulty4 ,illustration3 ,fig4 #aaj4--,timing ,diagram of ,typical ,eight-,cylinder ,v ,engine4 ,,how ,,an ,,engine ,,is ,,timed ,in timing a motor from the marks on the timing disc rim it is necessary to regulate the valves of but one cylinder at a time4 ,assuming that the disc is revolving in the direction of engine rotation1 and that the firing order of the cylinders is #a-c-d-b1 the operation of timing would be carried on as follows3 ,the crank-shaft would be revolved until the line marked ,exhaust opens #a and #d registered with the trammel on the motor bed4 ,at this point the exhaust-valve of either cylinder ,no4 #a or ,no4 #d should begin to open4 ,this can be easily determined by noting which of these cylinders holds the compressed charge ready for ignition4 ,assuming that the spark has occurred in cylinder ,no4 #a1 then when the fly-wheel is turned from the position to that in which the line marked ,exhaust opens #a and #d coincides with the trammel point1 the valve-plunger under the exhaust-valve of cylinder ,no4 #a should be adjusted in such a way that there is no clearance between it and the valve stem4 ,further movement of the wheel in the same direction should produce a lift of the exhaust valve4 ,the disc is turned about two hundred and twenty-five degrees1 or a little less than three-quarters of a revolution2 then the line marked ,exhaust closes #a and #d will register with the trammel point4 ,at this period the valve-plunger and the valve-stem should separate and a certain amount of clearance obtain between them4 ,the next cylinder to time would be ,no4 #c4 ,the crank-shaft is rotated until mark ,exhaust opens #b and #c comes in line with the trammel4 ,at this point the exhaust valve of cylinder ,no4 #c should be just about opening4 ,the closing is determined by rotating the shaft until the line ,exhaust closes #b and #c comes under the trammel4 ,this operation is carried on with all the cylinders1 it being well to remember that but one cylinder is working at a time and that a half-revolution of the fly-wheel corresponds to a full working stroke of all the cylinders1 and that while one is exhausting the others are respectively taking in a new charge1 compressing and exploding4 ,for instance1 if cylinder ,no4 #a has just completed its power-stroke1 the piston in cylinder ,no4 #c has reached the point where the gas may be ignited to advantage4 ,the piston of cylinder ,no4 #d1 which is next to fire1 is at the bottom of its stroke and will have inspired a charge1 while cylinder ,no4 #b1 which is the last to fire1 will have just finished expelling a charge of burned gas1 and will be starting the intake stroke4 ,this timing relates to a four-cylinder engine in order to simplify the explanation4 ,the timing instructions given apply only to the conventional motor types4 ,rotary cylinder engines1 especially the ,gnome monosoupape1 have a distinctive valve timing on account of the peculiarities of design4 ,,gnome ,,monosoupape ,,valve ,,timing ,in the present design of the ,gnome motor1 a cycle of operations somewhat different from that employed in the ordinary four-cycle engine is made use of1 says a writer in ,the ,automobile1 in describing the action of this power-plant4 ,this cycle does away with the need for the usual inlet valve and makes the engine operable with only a single valve1 hence the name monosoupape1 or single-valve4 ,the cycle is as follows3 ,a charge being compressed in the outer end of the cylinder or combustion chamber1 it is ignited by a spark produced by the spark-plug located in the side of this chamber1 and the burning charge expands as the piston moves down in the cylinder while the latter revolves around the crank-shaft4 ,when the piston is about half-way down on the power stroke1 the exhaust valve1 which is located in the center of the cylinder-head1 is mechanically opened1 and during the following upstroke of the piston the burnt gases are expelled from the cylinder through the exhaust valve directly into the atmosphere4 ,instead of closing at the end of the exhaust stroke1 or a few degrees thereafter1 the exhaust valve is held open for about two-thirds of the following inlet stroke of the piston1 with the result that fresh air is drawn through the exhaust valve into the cylinder4 ,when the cylinder is still #fe degrees from the end of the inlet half-revolution1 the exhaust valve closes4 ,as no more air can get into the cylinder1 and as the piston continues to move inwardly1 it is obvious that a partial vacuum is formed4 ,when the cylinder approaches within #bj degrees of the end of the inlet half-revolution a series of small inlet ports all around the circumference of the cylinder wall is uncovered by the top edge of the piston1 whereby the combustion chamber is placed in communication with the crank chamber4 ,as the pressure in the crank chamber is substantially atmospheric and that in the combustion chamber is below atmospheric1 there results a suction effect which causes the air from the crank chamber to flow into the combustion chamber4 ,the air in the crank chamber is heavily charged with gasoline vapor1 which is due to the fact that a spray nozzle connected with the gasoline supply tank is located inside the chamber4 ,the proportion of gasoline vapor in the air in the crank chamber is several times as great as in the ordinary combustible mixture drawn from a carburetor into the cylinder4 ,this extra-rich mixture is diluted in the combustion chamber with the air which entered it through the exhaust valve during the first part of the inlet stroke1 thus forming a mixture of the proper proportion for complete combustion4 ,the inlet ports in the cylinder wall remain open until #bj degrees of the compression half-revolution has been completed1 and from that moment to near the end of the compression stroke the gases are compressed in the cylinder4 ,near the end of the stroke ignition takes place and this completes the cycle4 ,the exact timing of the different phases of the cycle is shown in the diagram at ,fig4 #aaa4 ,it will be seen that ignition occurs substantially #bj degrees ahead of the outer dead center1 and expansion of the burning gases continues until #he degrees past the outer dead center1 when the piston is a little past half-stroke4 ,then the exhaust-valve opens and remains open for somewhat more than a complete revolution of the cylinders1 or1 to be exact1 for #cij degrees of cylinder travel1 until #aae degrees past the top dead center on the second revolution4 ,then for #de degrees of travel the charge within the cylinder is expanded1 whereupon the inlet ports are uncovered and remain open for #dj degrees of cylinder travel1 #bj degrees on each side of the inward dead center position4 ,,springless ,,valves ,springless valves are the latest development on ,french racing car engines1 and it is possible that the positively-operated types will be introduced on aviation engines also4 ,two makes of positively-actuated valves are shown at ,fig4 #aab4 ,the positive-valve motor differs from the conventional form by having no necessity for valve-springs1 as a cam not only assures the opening of the valve1 but also causes it to return to the valve-seat4 ,in this respect it is much like the sleeve-valve motor1 where the uncovering of the ports is absolutely positive4 ,the cars equipped with these valves were a success in long-distance auto races4 ,claims made for this type of valve mechanism include the possibility of a higher number of revolutions and consequently greater engine power4 ,with the spring-controlled1 single-cam operated valve a point is reached where the spring is not capable of returning the valve to its seat before the cam has again begun its opening movement4 ,it is possible to extend the limits considerably by using a light valve on a strong spring1 but the valve still remains a limiting factor in the speed of the motor4 ,illustration3 ,fig4 #aaa4--,timing ,diagram ,showing ,peculiar ,valve ,timing of ,gnome ,monosoupape ,rotary ,motor4 ,a part sectional view through a cylinder of an engine designed by ,g4 ,michaux is shown at ,fig4 #aab1 ,a4 ,there are two valves per cylinder1 inclined at about ten degrees from the vertical4 ,the valve-stems are of large diameter1 as owing to positive control1 there is no necessity of lightening this part in an unusual degree4 ,a single overhead cam-shaft has eight pairs of cams1 which are shown in detail at ,b4 ,for each valve there is a three-armed rocker1 one arm of which is connected to the stem of the valve and the two others are in contact respectively with the opening and closing cams4 ,the connection to the end of the valve-stem is made by a short connecting link1 which is screwed on to the end of the valve-stem and locked in position4 ,this allows some adjustment to be made between the valves and the actuating rocker4 ,it will be evident that one cam and one rocker arm produce the opening of the valve and that the corresponding rocker arm and cam result in the closing of the valve4 ,if the opening cam has the usual convex profile1 the closing cam has a correspondingly concave profile4 ,it will be noticed that a light valve-spring is shown in drawing4 ,this is provided to give a final seating to its valve after it has been closed by the cam4 ,this is not absolutely necessary1 as an engine has been run successfully without these springs4 ,the whole mechanism is contained within an overhead aluminum cover4 ,illustration3 ,fig4 #aab4--,two ,methods of ,operating ,valves by ,positive ,cam ,mechanism ,which ,closes as ,well as ,opens ,them4 ,the positive-valve system used on the ,de ,lage motor is shown at ,d4 ,in this the valves are actuated as shown in sectional views ,d and ,e4 ,the valve system is unique in that four valves are provided per cylinder1 two for exhaust and two for intake4 ,the valves are mounted side by side1 as shown at ,e1 so the double actuator member may be operated by a single set of cams4 ,the valve-operating member consists of a yoke having guide bars at the top and bottom4 ,the actuating cam works inside of this yoke4 ,the usual form of cam acts on the lower portion of the yoke to open the valve1 while the concave cam acts on the upper part to close the valves4 ,in this design provision is made for expansion of the valve-stems due to heat1 and these are not positively connected to the actuating member4 ,as shown at ,e1 the valves are held against the seat by short coil springs at the upper end of the stem4 ,these are very stiff and are only intended to provide for expansion4 ,a slight space is left between the top of the valve-stem and the portion of the operating member that bears against them when the regular profile cam exerts its pressure on the bottom of the valve-operating mechanism4 ,another novelty in this motor design is that the cam-shafts and the valve-operating members are carried in casing attached above the motor by housing supports in the form of small steel pillars4 ,the overhead cam-shafts are operated by means of bevel gearing4 ,,four ,,valves ,,per ,,cylinder ,illustration3 ,fig4 #aac4--;,diagram ,comparing ,two ,large ,valves and ,four ,small ,ones of ,practically the ,same ,area4 ,note ,how ,easily ,small ,valves are ,installed to ,open ,directly ,into the ,cylinder4 ,mention has been previously made of the sixteen-valve four-cylinder ,duesenberg motor and its great power output for the piston displacement4 ,this is made possible by the superior volumetric efficiency of a motor provided with four valves in each cylinder instead of but two4 ,this principle was thoroughly tried out in racing automobile motors1 and is especially valuable in permitting of greater speed and power output from simple four- and six-cylinder engines4 ,on eight- and twelve-cylinder types1 it is doubtful if the resulting complication due to using a very large number of valves would be worth while4 ,when extremely large valves are used1 as shown in diagram at ,fig4 #aac1 it is difficult to have them open directly into the cylinder1 and pockets are sometimes necessary4 ,a large valve would weigh more than two smaller valves having an area slightly larger in the aggregate2 it would require a stiffer valve spring on account of its greater weight4 ,a certain amount of metal in the valve-head is necessary to prevent warping2 therefore1 the inertia forces will be greater in the large valve than in the two smaller valves4 ,as a greater port area is obtained by the use of two valves1 the gases will be drawn into the cylinder or expelled faster than with a lesser area4 ,even if the areas are practically the same as in the diagram at ,fig4 #aac1 the smaller valves may have a greater lift without imposing greater stresses on the valve-operating mechanism and quicker gas intake and exhaust obtained4 ,the smaller valves are not affected by heat as much as larger ones are4 ,the quicker gas movements made possible1 as well as reduction of inertia forces1 permits of higher rotative speed1 and1 consequently1 greater power output for a given piston displacement4 ,the drawings at ,fig4 #aad show a sixteen-valve motor of the four-cylinder type that has been designed for automobile racing purposes1 and it is apparent that very slight modifications would make it suitable for aviation purposes4 ,part of the efficiency is due to the reduction of bearing friction by the use of ball bearings1 but the multiple-valve feature is primarily responsible for the excellent performance4 ,illustration3 ,fig4 #aad4--,sectional ,views of ,sixteen-,valve ,four-,cylinder ,automobile ,racing ,engine ,that ,may ,have ,possibilities for ,aviation ,service4 ,illustration3 ,fig4 #aae4--;,front ,view of ,curtiss ,,ox-#c ,aviation ,motor1 ,showing ,unconventional ,valve ,action by ,concentric ,push ,rod and ,pull ,tube4 ,,chapter ,,ix ,constructional ,details of ,pistons--,aluminum ,cylinders and ,pistons--,piston ,ring ,construction--,leak ,proof ,piston ,rings-- ,keeping ,oil ,out of ,combustion ,chamber--,connecting ,rod ,forms-- ,connecting ,rods for ,vee ,engines--,cam-,shaft and ,crank-,shaft ,designs--,ball ,bearing ,crank-,shafts--,engine ,base ,construction4 ,,constructional ,,details ,,of ,,pistons ,the piston is one of the most important parts of the gasoline motor inasmuch as it is the reciprocating member that receives the impact of the explosion and which transforms the power obtained by the combustion of gas to mechanical motion by means of the connecting rod to which it is attached4 ,the piston is one of the simplest elements of the motor1 and it is one component which does not vary much in form in different types of motors4 ,the piston is a cylindrical member provided with a series of grooves in which packing rings are placed on the outside and two bosses which serve to hold the wrist pin in its interior4 ,it is usually made of cast iron or aluminum1 though in some motors where extreme lightness is desired1 such as those used for aeronautic work1 it may be made of steel4 ,the use of the more resisting material enables the engineer to use lighter sections where it is important that the weight of this member be kept as low as possible consistent with strength4 ,illustration3 ,fig4 #aaf4--;,forms of ,pistons ,commonly ,employed in ,gasoline ,engines4 ,a--,dome ,head ,piston and ,three ,packing ,rings4 ,b--,flat ,top ,form ,almost ,universally ,used4 ,c--,concave ,piston ,utilized in ,knight ,motors and ,some ,having ,overhead ,valves4 ,d--,two-,cycle ,engine ,member with ,deflector ,plate ,cast ,integrally4 ,e--,differential of ,two-,diameter ,piston ,used in ,some ,engines ,operating on ,two-,cycle ,principle4 ,a number of piston types are shown at ,fig4 #aaf4 ,that at ,a has a round top and is provided with four split packing rings and two oil grooves4 ,a piston of this type is generally employed in motors where the combustion chamber is large and where it is desired to obtain a higher degree of compression than would be possible with a flat top piston4 ,this construction is also stronger because of the arched piston top4 ,the most common form of piston is that shown at ,b1 and it differs from that previously described only in that it has a flat top4 ,the piston outlined in section at ,c is a type used on some of the sleeve-valve motors of the ,knight pattern1 and has a concave head instead of the convex form shown at ,a4 ,the design shown at ,d in side and plan views is the conventional form employed in two-cycle engines4 ,the deflector plate on the top of the cylinder is cast integral and is utilized to prevent the incoming fresh gases from flowing directly over the piston top and out of the exhaust port1 which is usually opposite the inlet opening4 ,on these types of two-cycle engines where a two-diameter cylinder is employed1 the piston shown at ,e is used4 ,this is known as a differential piston1 and has an enlarged portion at its lower end which fits the pumping cylinder4 ,the usual form of deflector plate is provided at the top of the piston and one may consider it as two pistons in one4 ,illustration3 ,fig4 #aag4--,typical ,methods of ,piston ,pin ,retention ,generally ,used in ,engines of ,american ,design4 ,a--,single ,set ,screw and ,lock ,nut4 ,b--,set ,screw and ,check ,nut ,fitting ,groove in ,wrist ,pin4 ,c1 ,d--,two ,locking ,screws ,passing ,into ,interior of ,hollow ,wrist ,pin4 ,e--,split ,ring ,holds ,pin in ,place4 ,f--,use of ,taper ,expanding ,plugs ,outlined4 ,g--,spring ,pressed ,plunger ,type4 ,h--,piston ,pin ,pinned to ,connecting ,rod4 ,i--,wrist ,pin ,clamped in ,connecting ,rod ,small ,end by ,bolt4 ,illustration3 ,fig4 #aah4--,typical ,piston and ,connecting ,rod ,assembly4 ,illustration3 ,fig4 #aai4--,parts of ,sturtevant ,aviation ,engine4 ,a--,cylinder ,head ,showing ,valves4 ,b--,connecting ,rod4 ,c--,piston and ,rings4 ,one of the important conditions in piston design is the method of securing the wrist pin which is used to connect the piston to the upper end of the connecting rod4 ,various methods have been devised to keep the pin in place1 the most common of these being shown at ,fig4 #aag4 ,the wrist pin should be retained by some positive means which is not liable to become loose under the vibratory stresses which obtain at this point4 ,if the wrist pin was free to move it would work out of the bosses enough so that the end would bear against the cylinder wall4 ,as it is usually made of steel1 which is a harder material than cast iron used in cylinder construction1 the rubbing action would tend to cut a groove in the cylinder wall which would make for loss of power because it would permit escape of gas4 ,the wrist pin member is a simple cylindrical element that fits the bosses closely1 and it may be either hollow or solid stock4 ,a typical piston and connecting rod assembly which shows a piston in section also is given at ,fig4 #aah4 ,the piston of the ,sturtevant aeronautical motor is shown at ,fig4 #aai1 the aluminum piston of the ,thomas airplane motor with piston rings in place is shown at ,fig4 #abj4 ,a good view of the wrist pin and connecting rod are also given4 ,the iron piston of the ,gnome ,monosoupape airplane engine and the unconventional connecting rod assembly are clearly depicted at ,fig #aba4 ,illustration3 ,fig4 #abj4--;,aluminum ,piston and ,light ,but ,strong ,steel ,connecting ,rod and ,wrist ,pin of ,thomas ,aviation ,engine4 ,the method of retention shown at ,a is the simplest and consists of a set screw having a projecting portion passing into the wrist pin and holding it in place4 ,the screw is kept from turning or loosening by means of a check nut4 ,the method outlined at ,b is similar to that shown at ,a1 except that the wrist pin is solid and the point of the set screw engages an annular groove turned in the pin for its reception4 ,a very positive method is shown at ,c4 ,here the retention screws pass into the wrist pin and are then locked by a piece of steel wire which passes through suitable holes in the ends4 ,the method outlined at ,d is sometimes employed1 and it varies from that shown at ,c only in that the locking wire1 which is made of spring steel1 is passed through the heads of the locking screws4 ,some designers machine a large groove around the piston at such a point that when the wrist pin is put in place a large packing ring may be sprung in the groove and utilized to hold the wrist pin in place4 ,illustration3 ,fig4 #aba4--;,cast ,iron ,piston of ,monosoupape ,gnome ,engine ,installed ,on ,one of the ,short ,connecting ,rods4 ,the system shown at ,f is not so widely used as the simpler methods1 because it is more costly and does not offer any greater security when the parts are new than the simple lock shown at ,a4 ,in this a hollow wrist pin is used1 having a tapered thread cut at each end4 ,the wrist pin is slotted at three or four points1 for a distance equal to the length of the boss1 and when taper expansion plugs are screwed in place the ends of the wrist pin are expanded against the bosses4 ,this method has the advantage of providing a certain degree of adjustment if the wrist pin should loosen up after it has been in use for some time4 ,the taper plugs would be screwed in deeper and the ends of the wrist pin expanded proportionately to take up the loss motion4 ,the method shown at ,g is an ingenious one4 ,one of the piston bosses is provided with a projection which is drilled out to receive a plunger4 ,the wrist pin is provided with a hole of sufficient size to receive the plunger1 which is kept in place by means of a spring in back of it4 ,this makes a very positive lock and one that can be easily loosened when it is desired to remove the wrist pin4 ,to unlock1 a piece of fine rod is thrust into the hole at the bottom of the boss which pushes the plunger back against the spring until the wrist pin can be pushed out of the piston4 ,some engineers think it advisable to oscillate the wrist pin in the piston bosses1 instead of in the connecting rod small end4 ,it is argued that this construction gives more bearing surface at the wrist pin and also provides for more strength because of the longer bosses that can be used4 ,when this system is followed the piston pin is held in place by locking it to the connecting rod by some means4 ,at ,h the simplest method is outlined4 ,this consisted of driving a taper pin through both rod and wrist pin and then preventing it from backing out by putting a split cotter through the small end of the tapered locking pin4 ,another method1 which is depicted at ,i1 consists of clamping the wrist pin by means of a suitable bolt which brings the slit connecting rod end together as shown4 ,,aluminum ,,for ,,cylinders ,,and ,,pistons ,aluminum pistons outlined at ,fig4 #abb1 have replaced cast iron members in many airplane engines1 as these weigh about one-third as much as the cast iron forms of the same size1 while the reduction in the inertia forces has made it possible to increase the engine speed without correspondingly stressing the connecting rods1 crank-shaft and engine bearings4 ,illustration3 ,fig4 #abb4--,types of ,aluminum ,pistons ,used ,in ,aviation ,engines4 ,aluminum has not only been used for pistons1 but a number of motors will be built for the coming season that will use aluminum cylinder block castings as well4 ,of course1 the aluminum alloy is too soft to be used as a bearing for the piston1 and it will not withstand the hammering action of the valve4 ,this makes the use of cast iron or steel imperative in all motors4 ,when used in connection with an aluminum cylinder block the cast iron pieces are placed in the mould so that they act as cylinder liners and valve seats1 and the molten metal is poured around them when the cylinder is cast4 ,it is said that this construction results in an intimate bond between the cast iron and the surrounding aluminum metal4 ,steel liners may also be pressed into the aluminum cylinders after these are bored out to receive them4 ,aluminum has for a number of years been used in many motor car parts4 ,alloys have been developed that have greater strength than cast iron and that are not so brittle4 ,its use for manifolds and engine crank and gear cases has been general for a number of years4 ,at first thought it would seem as though aluminum would be entirely unsuited for use in those portions of internal combustion engines exposed to the heat of the explosion1 on account of the low melting point of that metal and its disadvantageous quality of suddenly wilting when a critical point in the temperature is reached4 ,those who hesitated to use aluminum on account of this defect lost sight of the great heat conductivity of that metal1 which is considerably more than that of cast iron4 ,it was found in early experiments with aluminum pistons that this quality of quick radiation meant that aluminum pistons remained considerably cooler than cast iron ones in service1 which was attested to by the reduced formation of carbon deposit thereon4 ,the use of aluminum makes possible a marked reduction in power plant weight4 ,a small four-cylinder engine which was not particularly heavy even with cast iron cylinders was found to weigh #ajj pounds less when the cylinder block1 pistons1 and upper half of the crank-case had been made of aluminum instead of cast iron4 ,aluminum motors are no longer an experiment1 as a considerable number of these have been in use on cars during the past year without the owners of the cars being apprised of the fact4 ,absolutely no complaint was made in any case of the aluminum motor and it was demonstrated1 in addition to the saving in weight1 that the motors cost no more to assemble and cooled much more efficiently than the cast iron form4 ,one of the drawbacks to the use of aluminum is its growing scarcity1 which results in making it a near precious metal4 ,,piston ,,ring ,,construction ,as all pistons must be free to move up and down in the cylinder with minimum friction1 they must be less in diameter than the bore of the cylinder4 ,the amount of freedom or clearance provided varies with the construction of the engine and the material the piston is made of1 as well as its size1 but it is usual to provide from 4#jje to 4#jaj of an inch to compensate for the expansion of the piston due to heat and also to leave sufficient clearance for the introduction of lubricant between the working surfaces4 ,obviously1 if the piston were not provided with packing rings1 this amount of clearance would enable a portion of the gases evolved when the charge is exploded to escape by it into the engine crank-case4 ,the packing members or piston rings1 as they are called1 are split rings of cast iron1 which are sprung into suitable grooves machined on the exterior of the piston1 three or four of these being the usual number supplied4 ,these have sufficient elasticity so that they bear tightly against the cylinder wall and thus make a gas-tight joint4 ,owing to the limited amount of surface in contact with the cylinder wall and the elasticity of the split rings the amount of friction resulting from the contact of properly fitted rings and the cylinder is not of enough moment to cause any damage and the piston is free to slide up and down in the cylinder bore4 ,illustration3 ,fig4 #abc4--,types of ,piston ,rings and ,ring ,joints4 ,a--,concentric ,ring4 ,b--,eccentrically ,machined ,form4 ,c--,lap ,joint ,ring4 ,d--,butt ,joint1 ,seldom ,used4 ,e--,diagonal ,cut ,member1 a ,popular ,form4 ,these rings are made in two forms1 as outlined at ,fig4 #abc4 ,the design shown at ,a is termed a concentric ring1 because the inner circle is concentric with the outer one and the ring is of uniform thickness at all points4 ,the ring shown at ,b is called an eccentric ring1 and it is thicker at one part than at others4 ,it has theoretical advantages in that it will make a tighter joint than the other form1 as it is claimed its expansion due to heat is more uniform4 ,the piston rings must be split in order that they may be sprung in place in the grooves1 and also to insure that they will have sufficient elasticity to take the form of the cylinder at the different points in their travel4 ,if the cylinder bore varies by small amounts the rings will spring out at the points where the bore is larger than standard1 and spring in at those portions where it is smaller than standard4 ,it is important that the joint should be as nearly gas-tight as possible1 because if it were not a portion of the gases would escape through the slots in the piston rings4 ,the joint shown at ,c is termed a lap joint1 because the ends of the ring are cut in such a manner that they overlap4 ,this is the approved joint4 ,the butt joint shown at ,d is seldom used and is a very poor form1 the only advantage being its cheapness4 ,the diagonal cut shown at ,e is a compromise between the very good form shown at ,c and the poor joint depicted at ,d4 ,it is also widely used1 though most constructors prefer the lap joint1 because it does not permit the leakage of gas as much as the other two types4 ,there seems to be some difference of opinion relative to the best piston ring type--some favoring the eccentric pattern1 others the concentric form4 ,the concentric ring has advantages from the lubricating engineer's point of view2 as stated by the ,platt ,washburn ,company in their text-book on engine lubrication1 the smaller clearance behind the ring possible with the ring of uniform section is advantageous4 ,fig4 #abd1 ,a1 shows a concentric piston ring in its groove4 ,since the ring itself is concentric with the groove1 very small clearance between the back of the ring and the bottom of its groove may be allowed4 ,small clearance leaves less space for the accumulation of oil and carbon deposits4 ,the gasket effect of this ring is uniform throughout the entire length of its edges1 which is its marked advantage over the eccentric ring4 ,this type of piston ring rarely burns fast in its groove4 ,there are a large number of different concentric rings manufactured of different designs and of different efficiency4 ,illustration3 ,fig4 #abd4--;,diagrams ,showing ,advantages of ,concentric ,piston ,rings4 ,figs4 #abd1 ,b and #abd1 ,c show eccentric rings assembled in the ring groove4 ,it will be noted that there is a large space between the thin ends of this ring and the bottom of the groove4 ,this empty space fills up with oil which in the case of the upper ring frequently is carbonized1 restricting the action of the ring and nullifying its usefulness4 ,the edges of the thin ends are not sufficiently wide to prevent rapid escape of gases past them4 ,in a practical way this leakage means loss of compression and noticeable drop in power4 ,when new and properly fitted1 very little difference can be noted between the tightness of eccentric and concentric rings4 ,nevertheless1 after several months' use1 a more rapid leakage will always occur past the eccentric than past the concentric4 ,if continuous trouble with the carbonization of cylinders1 smoking and sooting of spark-plugs is experienced1 it is a sure indication that mechanical defects exist in the engine1 assuming of course1 that a suitable oil has been used4 ,such trouble can be greatly lessened1 if not entirely eliminated1 by the application of concentric rings 7lap joint71 of any good make1 properly fitted into the grooves of the piston4 ,too much emphasis cannot be put upon this point4 ,if the oil used in the engine is of the correct viscosity1 and serious carbon deposit1 smoking1 etc41 still result1 the only certain remedy then is to have the cylinders rebored and fitted with properly designed1 oversized pistons and piston rings4 ,,leak-,,proof ,,piston ,,rings ,in order to reduce the compression loss and leakage of gas by the ordinary simple form of diagonal or lap joint one-piece piston ring a number of compound rings have been devised and are offered by their makers to use in making replacements4 ,the leading forms are shown at ,fig4 #abe4 ,that shown at ,a is known as the ,statite and consists of three rings1 one carried inside while the other two are carried on the outside4 ,the ring shown at ,b is a double ring and is known as the ,mc,cadden4 ,this is composed of two thin concentric lap joint rings so disposed relative to each other that the opening in the inner ring comes opposite to the opening in the outer ring4 ,the form shown at ,c is known as the ,leektite1 and is a single ring provided with a peculiar form of lap and dove tail joint4 ,the ring shown at ,d is known as the ,dunham and is of the double concentric type being composed of two rings with lap joints which are welded together at a point opposite the joint so that there is no passage by which the gas can escape4 ,the ,burd high compression ring is shown at ,e4 ,the joints of these rings are sealed by means of an ,h-shaped coupler of bronze which closes the opening4 ,the ring ends are made with tongues which interlock with the coupling4 ,the ring shown at ,f is called the ,evertite and is a three-piece ring composed of three members as shown in the sectional view below the ring4 ,the main part or inner ring has a circumferential channel in which the two outer rings lock1 the resulting cross-section being rectangular just the same as that of a regular pattern ring4 ,all three rings are diagonally split and the joints are spaced equally and the distances maintained by small pins4 ,this results in each joint being sealed by the solid portion of the other rings4 ,illustration3 ,fig4 #abe4--,leak-,proof and ,other ,compound ,piston ,rings4 ,the use of a number of light steel rings instead of one wide ring in the groove is found on a number of automobile power plants1 but as far as known1 this construction is not used in airplane power plants4 ,it is contended that where a number of light rings is employed a more flexible packing means is obtained and the possibility of leakage is reduced4 ,rings of this design are made of square section steel wire and are given a spring temper4 ,owing to the limited width the diagonal cut joint is generally employed instead of the lap joint which is so popular on wider rings4 ,,keeping ,,oil ,,out ,,of ,,combustion ,,chambers ,an examination of the engine design that is economical in oil consumption discloses the use of tight piston rings1 large centrifugal rings on the crank-shaft where it passes through the case1 ample cooling fins in the pistons1 vents between the crank-case chamber and the valve enclosures1 etc4 ,briefly put1 cooling of the oil in this engine has been properly cared for and leakage reduced to a minimum4 ,to be specific regarding details of design3 ,oil surplus can be kept out of the explosion chambers by leaving the lower edge of the piston skirt sharp and by the use of a shallow groove 7,c71 ,fig4 #abf1 just below the lower piston ring4 ,small holes are bored through the piston walls at the base of this groove and communicate with the crank-case4 ,the similarity of the sharp edges of piston skirt 7,d7 and piston ring to a carpenter's plane bit1 makes their operation plain4 ,illustration3 ,fig4 #abf4--,sectional ,view of ,engine ,showing ,means of ,preventing ,oil ,leakage ,by ,piston ,rings4 ,the cooling of oil in the sump 7,a7 can be accomplished most effectively by radiating fins on its outer surface4 ,the lower crank-case should be fully exposed to the outer air4 ,a settling basin for sediment 7,b7 should be provided having a cubic content not less than one-tenth of the total oil capacity as outlined at ,fig4 #abf4 ,the depth of this basin should be at least #b-a_/b inches1 and its walls vertical1 as shown1 to reduce the mixing of sediment with the oil in circulation4 ,the inlet opening to the oil pump should be near the top of the sediment basin in order to prevent the entrance into the pump with the oil of any solid matter or water condensed from the products of combustion4 ,this sediment basin should be drained after every five to seven hours air service of an airplane engine4 ,concerning filtering screens there is little to be said1 save that their areas should be ample and the mesh coarse enough 7one-sixteenth of an inch7 to offer no serious resistance to the free flow of cold or heavy oil through them2 otherwise the oil in the crank-case may build up above them to an undesirable level4 ,the necessary frequency of draining and flushing out the oil sump differs greatly with the age 7condition7 of the engine and the suitability of the oil used4 ,in broad terms1 the oil sump of a new engine should be thoroughly drained and flushed with kerosene at the end of the first #bjj miles1 next at the end of #ejj miles and thereafter every #a1jjj miles4 ,while these instructions apply specifically to automobile motors1 it is very good practice to change the oil in airplane engines frequently4 ,in many cases1 the best results have been secured when the oil supply is completely replenished every five hours that the engine is in operation4 ,,connecting ,,rod ,,forms ,the connecting rod is the simple member that joins the piston to the crank-shaft and which transmits the power imparted to the piston by the explosion so that it may be usefully applied4 ,it transforms the reciprocating movement of the piston to a rotary motion at the crank-shaft4 ,a typical connecting rod and its wrist pin are shown at ,fig4 #abj4 ,it will be seen that it has two bearings1 one at either end4 ,the small end is bored out to receive the wrist pin which joins it to the piston1 while the large end has a hole of sufficient size to go on the crank-pin4 ,the airplane and automobile engine connecting rod is invariably a steel forging1 though in marine engines it is sometimes made a steel or high tensile strength bronze casting4 ,in all cases it is desirable to have softer metals than the crank-shaft and wrist pin at the bearing point1 and for this reason the connecting rod is usually provided with bushings of anti-friction or white metal at the lower end1 and bronze at the upper4 ,the upper end of the connecting rod may be one piece1 because the wrist pin can be introduced after it is in place between the bosses of the piston4 ,the lower bearing must be made in two parts in most cases1 because the crank-shaft cannot be passed through the bearing owing to its irregular form4 ,the rods of the ,gnome engine are all one piece types1 as shown at ,fig4 #abg1 owing to the construction of the mother rod which receives the crank-pins4 ,the complete connecting rod assembly is shown in ,fig4 #aba1 also at ,a1 ,fig4 #abg4 ,the mother rod1 with one of the other rods in place and one about to be inserted1 is shown at ,fig4 #abg1 ,b4 ,the built-up crank-shaft which makes this construction feasible is shown at ,fig4 #abg1 ,c4 ,illustration3 ,fig4 #abg4--;,connecting ,rod and ,crank-,shaft ,construction of ,gnome ,monosoupape ,engine4 ,some of the various designs of connecting rods that have been used are shown at ,fig4 #abh4 ,that at ,a is a simple form often employed in single-cylinder motors1 having built-up crank-shafts4 ,both ends of the connecting rod are bushed with a one-piece bearing1 as it can be assembled in place before the crank-shaft assembly is built up4 ,a built-up crank-shaft such as this type of connecting rod would be used with is shown at ,fig4 #ajf4 ,the pattern shown at ,b is one that has been used to some extent on heavy work1 and is known as the marine type4 ,it is made in three pieces1 the main portion being a steel forging having a flanged lower end to which the bronze boxes are secured by bolts4 ,the modified marine type depicted at ,c is the form that has received the widest application in automobile and aviation engine construction4 ,it consists of two pieces1 the main member being a steel drop forging having the wrist-pin bearing and the upper crank-pin bearing formed integral1 while the lower crank-pin bearing member is a separate forging secured to the connecting rod by bolts4 ,in this construction bushings of anti-friction metal are used at the lower end1 and a bronze bushing is forced into the upper- or wrist-pin end4 ,the rod shown at ,d has also been widely used4 ,it is similar in construction to the form shown at ,c1 except that the upper end is split in order to permit of a degree of adjustment of the wrist-pin bushing1 and the lower bearing cap is a hinged member which is retained by one bolt instead of two4 ,when it is desired to assemble it on the crank-shaft the lower cap is swung to one side and brought back into place when the connecting rod has been properly located4 ,sometimes the lower bearing member is split diagonally instead of horizontally1 such a construction being outlined at ,e4 ,illustration3 ,fig4 #abh4--;,connecting ,rod ,types ,summarized4 ,a--,single ,connecting ,rod ,made in ,one ,piece1 ,usually ,fitted in ,small ,single-,cylinder ,engines ,having ,built-,up ,crank-,shafts4 ,b--,marine ,type1 a ,popular ,form on ,heavy ,engines4 ,c--,conventional ,automobile ,type1 a ,modified ,marine ,form4 ,d--,type ,having ,hinged ,lower ,cap and ,split ,wrist ,pin ,bushing4 ,e--,connecting ,rod ,having ,diagonally ,divided ,big ,end4 ,f--,ball-,bearing ,rod4 ,g--,sections ,showing ,structural ,shapes ,commonly ,employed in ,connecting ,rod ,construction4 ,in a number of instances1 instead of plain bushed bearings anti-friction forms using ball or rollers have been used at the lower end4 ,a ball-bearing connecting rod is shown at ,f4 ,the big end may be made in one piece1 because if it is possible to get the ball bearing on the crank-pins it will be easy to put the connecting rod in place4 ,ball bearings are not used very often on connecting rod big ends because of difficulty of installation1 though when applied properly they give satisfactory service and reduce friction to a minimum4 ,one of the advantages of the ball bearing is that it requires no adjustment1 whereas the plain bushings depicted in the other connecting rods must be taken up from time to time to compensate for wear4 ,this can be done in forms shown at ,b1 ,c1 ,d1 and ,e by bringing the lower bearing caps closer to the upper one and scraping out the brasses to fit the shaft4 ,a number of liners or shims of thin brass or copper stock1 varying from 4#jjb inch to 4#jje inch1 are sometimes interposed between the halves of the bearings when it is first fitted to the crank-pin4 ,as the brasses wear the shims may be removed and the portions of the bearings brought close enough together to take up any lost motion that may exist1 though in some motors no shims are provided and depreciation can be remedied only by installing new brasses and scraping to fit4 ,illustration3 ,fig4 #abi4--;,double ,connecting ,rod ,assembly ,for ,use ,on ,single ,crank-,pin of ,vee ,engine4 ,the various structural shapes in which connecting rods are formed are shown in section at ,g4 ,of these the ,i section is most widely used in airplane engines1 because it is strong and a very easy shape to form by the drop-forging process or to machine out of the solid bar when extra good steel is used4 ,where extreme lightness is desired1 as in small high-speed motors used for cycle propulsion1 the section shown at the extreme left is often used4 ,if the rod is a cast member as in some marine engines1 the cross1 hollow cylinder1 or ,u sections are sometimes used4 ,if the sections shown at the right are employed1 advantage is often taken of the opportunity for passing lubricant through the center of the hollow round section on vertical motors or at the bottom of the ,u section1 which would be used on a horizontal cylinder power plant4 ,illustration3 ,fig4 #acj4--;,another ,type of ,double ,connecting ,rod for ,vee ,engines4 ,connecting rods of ,vee engines are made in two distinct styles4 ,the forked or scissors joint rod assembly is employed when the cylinders are placed directly opposite each other4 ,the blade rod1 as shown at ,fig4 #abi1 fits between the lower ends of the forked rod1 which oscillate on the bearing which encircles the crank-pin4 ,the lower end of the blade rod is usually attached to the bearing brasses1 the ends of the forked rod move on the outer surfaces of the brasses4 ,another form of rod devised for use under these conditions is shown at ,fig4 #acj and installed in an aviation engine at ,fig4 #acb4 ,in this construction the shorter rod is attached to a boss on the master rod by a short pin to form a hinge and to permit the short rod to oscillate as the conditions dictate4 ,this form of rod can be easily adjusted when the bearing depreciates1 a procedure that is difficult with the forked type rod4 ,the best practice1 in the writer's opinion1 is to stagger the cylinders and use side-by-side rods as is done in the ,curtiss engine4 ,each rod may be fitted independently of the other and perfect compensation for wear of the big ends is possible4 ,illustration3 ,fig4 #aca4--,part ,sectional ,view of ,wisconsin ,aviation ,engine1 ,showing ,four-,bearing ,crank-,shaft1 ,overhead ,cam-,shaft1 and ,method of ,combining ,cylinders in ,pairs4 ,illustration3 ,fig4 #acb4--,part ,sectional ,view of ,renault ,twelve-,cylinder ,water-,cooled ,engine1 ,showing ,connecting ,rod ,construction and ,other ,important ,internal ,parts4 ,,cam-,,shaft ,,and ,,crank-,,shaft ,,design ,before going extensively into the subject of crank-shaft construction it will be well to consider cam-shaft design1 which is properly a part of the valve system and which has been considered in connection with the other elements which have to do directly with cylinder construction to some extent4 ,cam-shafts are usually simple members carried at the base of the cylinder in the engine case of ,vee type motors by suitable bearings and having the cams employed to lift the valves attached at intervals4 ,a typical cam-shaft design is shown at ,fig4 #acc4 ,two main methods of cam-shaft construction are followed--that in which the cams are separate members1 keyed and pinned to the shaft1 and the other where the cams are formed integral1 the latter being the most suitable for airplane engine requirements4 ,illustration3 ,fig4 #acc4--,typical ,cam-,shaft1 with ,valve ,lifting ,cams and ,gears to ,operate ,auxiliary ,devices ,forged ,integrally4 ,the cam-shafts shown at ,figs4 #acc and #acd1 ,b1 are of the latter type1 as the cams are machined integrally4 ,in this case not only the cams but also the gears used in driving the auxiliary shafts are forged integral4 ,this is a more expensive construction1 because of the high initial cost of forging dies as well as the greater expense of machining4 ,it has the advantage over the other form in which the cams are keyed in place in that it is stronger1 and as the cams are a part of the shaft they can never become loose1 as might be possible where they are separately formed and assembled on a simple shaft4 ,illustration3 ,fig4 #acd4--;,important ,parts of ,duesenberg ,aviation ,engine4 ,a--,three ,main ,bearing ,crank-,shaft4 ,b--,cam-,shaft with ,integral ,cams4 ,c--,piston and ,connecting ,rod ,assembly4 ,d--,valve ,rocker ,group4 ,e--,piston4 ,f--,main ,bearing ,brasses4 ,the importance of the crank-shaft has been previously considered1 and some of its forms have been shown in views of the motors presented in earlier portions of this work4 ,the crank-shaft is one of the parts subjected to the greatest strain and extreme care is needed in its construction and design1 because practically the entire duty of transmitting the power generated by the motor to the gearset devolves upon it4 ,crank-shafts are usually made of high tensile strength steel of special composition4 ,they may be made in four ways1 the most common being from a drop or machine forging which is formed approximately to the shape of the finished shaft and in rare instances 7experimental motors only7 they may be steel castings4 ,sometimes they are made from machine forgings1 where considerably more machine work is necessary than would be the case where the shaft is formed between dies4 ,some engineers favor blocking the shaft out of a solid slab of metal and then machining this rough blank to form4 ,in some radial-cylinder motors of the ,gnome and ,le ,rhone type the crank-shafts are built up of two pieces1 held together by taper fastenings or bolts4 ,illustration3 ,fig4 #ace4--,showing ,method of ,making ,crank-,shaft4 ,a--,the ,rough ,steel ,forging ,before ,machining4 ,b--,the ,finished ,six-,throw1 ,seven-,bearing ,crank-,shaft4 ,the form of the shaft depends on the number of cylinders and the form has material influence on the method of construction4 ,for instance1 a four-cylinder crank-shaft could be made by either of the methods outlined4 ,on the other hand1 a three- or six-cylinder shaft is best made by the machine forging process1 because if drop forged or cut from the blank it will have to be heated and the crank throws bent around so that the pins will lie in three planes one hundred and twenty degrees apart1 while the other types described need no further attention1 as the crank-pins lie in planes one hundred and eighty degrees apart4 ,this can be better understood by referring to ,fig4 #ace1 which shows a six-cylinder shaft in the rough and finished stages4 ,at ,a the appearance of the machine forging before any of the material is removed is shown1 while at ,b the appearance of the finished crank-shaft is clearly depicted4 ,the built-up crank-shaft is seldom used on multiple-cylinder motors1 except in some cases where the crank-shafts revolve on ball bearings as in some automobile racing engines4 ,illustration3 ,fig4 #acf4--,showing ,form of ,crank-,shaft for ,twin-,cylinder ,opposed ,power ,plant4 ,illustration3 ,fig4 #acg4--;,crank-,shaft of ,thomas-,morse ,eight-,cylinder ,vee ,engine4 ,crank-shaft form will vary with a number of cylinders and it is possible to use a number of different arrangements of crank-pins and bearings for the same number of cylinders4 ,the simplest form of crank-shaft is that used on simple radial cylinder motors as it would consist of but one crank-pin1 two webs1 and the crank-shaft4 ,as the number of cylinders increase in ,vee motors as a general rule more crank-pins are used4 ,the crank-shaft that would be used on a two-cylinder opposed motor is shown at ,fig4 #acf4 ,this has two throws and the crank-pins are spaced #ahj degrees apart4 ,the bearings are exceptionally long4 ,four-cylinder crank-shafts may have two1 three or five main bearings and three or four crank-pins4 ,in some forms of two-bearing crank-shafts1 such as used when four-cylinders are cast in a block1 or unit casting1 two of the pistons are attached to one common crank-pin1 so that in reality the crank-shaft has but three crank-pins4 ,a typical three bearing1 four-cylinder crank-shaft is shown at ,fig4 #acd1 ,a4 ,the same type can be used for an eight-cylinder ,vee engine1 except for the greater length of crank-pins to permit of side by side rods as shown at ,fig4 #acg4 ,six cylinder vertical tandem and twelve-cylinder ,vee engine crank-shafts usually have four or seven main bearings depending upon the disposition of the crank-pins and arrangement of cylinders4 ,at ,fig4 #ach1 ,a1 the bottom view of a twelve-cylinder engine with bottom half of crank case removed is given4 ,this illustrates clearly the arrangement of main bearings when the crank-shaft is supported on four journals4 ,the crank-shaft shown at ,fig4 #ach1 ,b1 is a twelve-cylinder seven-bearing type4 ,illustration3 ,fig4 #ach4--;,crank-,case and ,crank-,shaft ,construction for ,twelve-,cylinder ,motors4 ,a--,duesenberg4 ,b--,curtiss4 ,illustration3 ,fig4 #aci4--;,counterbalanced ,crank-,shafts ,reduce ,engine ,vibration and ,permit of ,higher ,rotative ,speeds4 ,in some automobile engines1 extremely good results have been secured in obtaining steady running with minimum vibration by counterbalancing the crank-shafts as outlined at ,fig4 #aci4 ,the shaft at ,a is a type suitable for a high speed four-cylinder vertical or an eight-cylinder ,vee type4 ,that at ,b is for a six-cylinder vertical or a twelve-cylinder ,v with scissors joint rods4 ,if counterbalancing crank-shafts helps in an automobile engine1 it should have advantages of some moment in airplane engines1 even though the crank-shaft weight is greater4 ,,ball-,,bearing ,,crank-,,shafts ,while crank-shafts are usually supported in plain journals there seems to be a growing tendency of late to use anti-friction bearings of the ball type for their support4 ,this is especially noticeable on block motors where but two main bearings are utilized4 ,when ball bearings are selected with proper relation to the load which obtains they will give very satisfactory service4 ,they permit the crank-shaft to turn with minimum friction1 and if properly selected will never need adjustment4 ,the front end is supported by a bearing which is clamped in such a manner that it will take a certain amount of load in a direction parallel to the axis of the shaft1 while the rear end is so supported that the outer race of the bearing has a certain amount of axial freedom or float4 ,the inner race or cone of each bearing is firmly clamped against shoulders on the crank-shaft4 ,at the front end of the crank-shaft timing gear and a suitable check nut are used1 while at the back end the bearing is clamped by a threaded retention member between the fly-wheel and a shoulder on the crank-shaft4 ,the fly-wheel is held in place by a taper and key retention4 ,the ball bearings are carried in a light housing of bronze or malleable iron1 which in turn are held in the crank-case by bolts4 ,the ,renault engine uses ball bearings at front and rear ends of the crank-shaft1 but has plain bearings around intermediate crank-shaft journals4 ,the rotary engines of the ,gnome1 ,le ,rhone and ,clerget forms would not be practical if ball bearings were not used as the bearing friction and consequent depreciation would be very high4 ,,engine-,,base ,,construction ,one of the important parts of the power plant is the substantial casing or bed member1 which is employed to support the cylinders and crank-shaft and which is attached directly to the fuselage engine supporting members4 ,this will vary widely in form1 but as a general thing it is an approximately cylindrical member which may be divided either vertically or horizontally in two or more parts4 ,airplane engine crank-cases are usually made of aluminum1 a material which has about the same strength as cast iron1 but which only weighs a third as much4 ,in rare cases cast iron is employed1 but is not favored by most engineers because of its brittle nature1 great weight and low resistance to tensile stresses4 ,where exceptional strength is needed alloys of bronze may be used1 and in some cases where engines are produced in large quantities a portion of the crank-case may be a sheet steel or aluminum stamping4 ,illustration3 ,fig4 #adj4--,view of ,thomas #ace ,horse-,power ,aeromotor1 ,model #h1 ,showing ,conventional ,method of ,crank-,case ,construction4 ,illustration3 ,fig4 #ada4--,views of ,upper ,half of ,thomas ,aeromotor ,crank-,case4 ,crank-cases are always large enough to permit the crank-shaft and parts attached to it to turn inside and obviously its length is determined by the number of cylinders and their disposition4 ,the crank-case of the radial cylinder or double-opposed cylinder engine would be substantially the same in length4 ,that of a four-cylinder will vary in length with the method of casting the cylinder4 ,when the four-cylinders are cast in one unit and a two-bearing crank-shaft is used1 the crank-case is a very compact and short member4 ,when a three-bearing crank-shaft is utilized and the cylinders are cast in pairs1 the engine base is longer than it would be to support a block casting1 but is shorter than one designed to sustain individual cylinder castings and a five-bearing crank-shaft4 ,it is now common construction to cast an oil container integral with the bottom of the engine base and to draw the lubricating oil from it by means of a pump1 as shown at ,fig4 #adj4 ,the arms by which the motor is supported in the fuselage are substantial-ribbed members cast integrally with the upper half4 ,illustration3 ,fig4 #adb4--,method of ,constructing ,eight-,cylinder ,vee ,engine1 ,possible if ,aluminum ,cylinder and ,crank-,case ,castings are ,used4 ,illustration3 ,fig4 #adc4--,simple and ,compact ,crank-,case1 ,possible ,when ,radial ,cylinder ,engine ,design is ,followed4 ,the approved method of crank-case construction favored by the majority of engineers is shown at the top of ,fig4 #ada1 bottom side up4 ,the upper half not only forms a bed for the cylinder but is used to hold the crank-shaft as well4 ,in the illustration1 the three-bearing boxes form part of the case1 while the lower brasses are in the form of separately cast caps retained by suitable bolts4 ,in the construction outlined the bottom part of the case serves merely as an oil container and a protection for the interior mechanism of the motor4 ,the cylinders are held down by means of studs screwed into the crank-case top1 as shown at ,fig4 #ada1 lower view4 ,if the aluminum cylinder motor has any future1 the method of construction outlined at ,fig4 #adb1 which has been used in cast iron for an automobile motor1 might be used for an eight-cylinder ,vee engine for airplane use4 ,the simplicity of the crank-case needed for a revolving cylinder motor and its small weight can be well understood by examination of the illustration at ,fig4 #adc1 which shows the engine crank-case for the nine-cylinder ,monosoupape ,gnome engine4 ,this consists of two accurately machined forgings held together by bolts as clearly indicated4 ,,chapter ,x ,power ,plant ,installation--,curtiss ,,ox-#b ,engine ,mounting and ,operating ,rules--,standard ,s4 ,a4 ,e4 ,engine ,bed ,dimensions-- ,hall-,scott ,engine ,installation and ,operation--,fuel ,system ,rules --,ignition ,system--,water ,system--,preparations to ,start ,engine-- ,mounting ,radial and ,rotary ,engines--,practical ,hints to ,locate ,engine ,troubles--,all ,engine ,troubles ,summarized--,location of ,engine ,troubles ,made ,easy4 ,the proper installation of the airplane power plant is more important than is generally supposed1 as while these engines are usually well balanced and run with little vibration1 it is necessary that they be securely anchored and that various connections to the auxiliary parts be carefully made in order to prevent breakage from vibration and that attendant risk of motor stoppage while in the air4 ,the type of motor to be installed determines the method of installation to be followed4 ,as a general rule six-cylinder vertical engine and eight-cylinder ,vee type are mounted in substantially the same way4 ,the radial1 fixed cylinder forms and the radial1 rotary cylinder ,gnome and ,le ,rhone rotary types require an entirely different method of mounting4 ,some unconventional mountings have been devised1 notably that shown at ,fig4 #add1 which is a six-cylinder ,german engine that is installed in just the opposite way to that commonly followed4 ,the inverted cylinder construction is not generally followed because even with pressure feed1 dry crank-case type lubricating system there is considerable danger of over-lubrication and of oil collecting and carbonizing in the combustion chamber and gumming up the valve action much quicker than would be the case if the engine was operated in the conventional upright position4 ,the reason for mounting an engine in this way is to obtain a lower center of gravity and also to make for more perfect streamlining of the front end of the fuselage in some cases4 ,it is rather doubtful if this slight advantage will compensate for the disadvantages introduced by this unusual construction4 ,it is not used to any extent now but is presented merely to show one of the possible systems of installing an airplane engine4 ,illustration3 ,fig4 #add4--,unconventional ,mounting of ,german ,inverted ,cylinder ,motor4 ,illustration3 ,fig4 #ade4--;,how ,curtiss ,model ,,ox-#b ,motor is ,installed in ,fuselage of ,curtiss ,tractor ,biplane4 ,note ,similarity of ,mounting to ,automobile ,power ,plant4 ,in a number of airplanes of the tractor-biplane type the power plant installation is not very much different than that which is found in automobile practice4 ,the illustration at ,fig4 #ade is a very clear representation of the method of mounting the ,curtiss eight-cylinder #ij ,h4 ,p4 or model ,,ox-#b engine in the fuselage of the ,curtiss ,,jn-#d tractor biplane which is so generally used in the ,united ,states as a training machine4 ,it will be observed that the fuel tank is mounted under a cowl directly behind the motor and that it feeds the carburetor by means of a flexible fuel pipe4 ,as the tank is mounted higher than the carburetor1 it will feed that member by gravity4 ,the radiator is mounted at the front end of the fuselage and connected to the water piping on the motor by the usual rubber hose connections4 ,an oil pan is placed under the engine and the top is covered with a hood just as in motor car practice4 ,the panels of aluminum are attached to the sides of the fuselage and are supplied with doors which open and provide access to the carburetor1 oil-gauge and other parts of the motor requiring inspection4 ,the complete installation with the power plant enclosed is given at ,fig4 #adf1 and in this it will be observed that the exhaust pipes are connected to discharge members that lead the gases above the top plane4 ,in the engine shown at ,fig4 #ade the exhaust flows directly into the air at the sides of the machine through short pipes bolted to the exhaust gas outlet ports4 ,the installation of the radiator just back of the tractor screw insures that adequate cooling will be obtained because of the rapid air flow due to the propeller slip stream4 ,illustration3 ,fig4 #adf4--,latest ,model of ,curtiss ,,jn-#d ,training ,machine1 ,showing ,thorough ,enclosure of ,power ,plant and ,method of ,disposing of the ,exhaust ,gases4 ,,installation ,,of ,,curtiss ,,ox-#b ,,engine ,illustration3 ,fig4 #adg4--;,front ,view of ,l4 ,w4 ,f4 ,tractor ,biplane ,fuselage1 ,showing ,method of ,installing ,thomas ,aeromotor and ,method of ,disposing of ,exhaust ,gases4 ,the following instructions are given in the ,curtiss ,instruction ,book for installing the ,,ox-#b engine and preparing it for flights1 and taken in connection with the very clear illustration presented no difficulty should be experienced in understanding the proper installation1 and mounting of this power plant4 ,the bearers or beds should be #b inches wide by #c inches deep1 preferably of laminated hard wood1 and placed #aa-e_/h inches apart4 ,they must be well braced4 ,the six arms of the base of the motor are drilled for #c_/h-;inch bolts1 and none but this size should he used4 #a4 ,anchoring the ,motor4 ,put the bolts in from the bottom1 with a large washer under the head of each so the head cannot cut into the wood4 ,on every bolt use a castellated nut and a cotter pin1 or an ordinary nut and a lock washer1 so the bolt will not work loose4 ,always set motor in place and fasten before attaching any auxiliary apparatus1 such as carburetor1 etc4 #b4 ,inspecting the ,ignition-,switch ,wires4 ,the wires leading from the ignition switch must be properly connected--one end to the motor body for ground1 and the other end to the post on the breaker box of the magneto4 #c4 ,filling the ,radiator4 ,be sure that the water from the radiator fills the cylinder jackets4 ,pockets of air may remain in the cylinder jackets even though the radiator may appear full4 ,turn the motor over a few times by hand after filling the radiator1 and then add more water if the radiator will take it4 ,the air pockets1 if allowed to remain1 may cause overheating and develop serious trouble when the motor is running4 #d4 ,filling the ,oil ,reservoir4 ,oil is admitted into the crank-case through the breather tube at the rear4 ,it is well to strain all oil put into the crank-case4 ,in filling the oil reservoir be sure to turn the handle on the oil sight-gauge till it is at right angles with the gauge4 ,the oil sight-gauge is on the side of the lower half of the crank-case4 ,put in about #c gallons of the best obtainable oil1 ,mobile ,b recommended4 ,it is important to remember that the very best oil is none too good4 #e4 ,oiling ,exposed ,moving ,parts4 ,oil all rocker-arm bearings before each flight4 ,a little oil should be applied where the push rods pass through the stirrup straps4 #f4 ,filling the ,gasoline ,tanks4 ,be certain that all connections in the gasoline system are tight4 #g4 ,turning on the ,gasoline4 ,open the cock leading from the gasoline tank to the carburetor4 #h4 ,charging the ,cylinders4 ,with the ignition switch ,,off1 prime the motor by squirting a little gasoline in each exhaust port and then turn the propeller backward two revolutions4 ,never open the exhaust valve by operating the rocker-arm by hand1 as the push-rod is liable to come out of its socket in the cam follower and bend the rocker-arm when the motor turns over4 #i4 ,starting the ,motor by ,hand4 ,always retard the spark part way1 to prevent back-firing1 by pulling forward the wire attached to the breaker box4 ,failure to so retard the spark in starting may result in serious injury to the operator4 ,turn on the ignition switch with throttle partly open2 give a quick1 strong pull down and outward on the starting crank or propeller4 ,as soon as the motor is started advance the spark by releasing the retard wire4 #aj4 ,oil ,circulation4 ,let the motor run at low speed for a few minutes in order to establish oil circulation in all bearings4 ,with all parts functioning properly1 the throttle may be opened gradually for warming up before flight4 ,,standard ,s4,a4,e4 ,,engine ,,bed ,,dimensions ,the ,society of ,automotive ,engineers have made efforts to standardize dimensions of bed timbers for supporting power plant in an aeroplane4 ,owing to the great difference in length no standardization is thought possible in this regard4 ,the dimensions recommended are as follows3 ,distance between timbers #ab in4 #ad in4 #af in4 ,width of bed timbers #a-a_/b in4 #a-c_/d in4 #b in4 ,distance between centers of bolts #ac-a_/b in4 #ae-c_/d in4 #ah in4 ,it will be evident that if any standard of this nature were adopted by engine builders that the designers of fuselage could easily arrange their bed timbers to conform to these dimensions1 whereas it would be difficult to have them adhere to any standard longitudinal dimensions which are much more easily varied in fuselages than the transverse dimensions are4 ,it1 however1 should be possible to standardize the longitudinal positions of the holding down bolts as the engine designer would still be able to allow himself considerable space fore-and-aft of the bolts4 ,illustration3 ,fig4 #adh4--;,end ,elevation of ,hall-,scott ,a-#g ,four-,cylinder ,motor1 with ,installation ,dimensions4 ,,hall-,,scott ,,engine ,,installation ,illustration3 ,fig4 #adi4--,plan and ,side ,elevation of ,hall-,scott ,a-#g ,four-,cylinder ,airplane ,engine1 with ,installation ,dimensions4 ,the very thorough manner in which installation diagrams are prepared by the leading engine makers leaves nothing to the imagination4 ,the dimensions of the ,hall-,scott four-cylinder airplane engine are given clearly in our inch measurements with the metric equivalents at ,figs4 #adh and #adi1 the former showing a vertical elevation while the latter has a plan view and side elevation4 ,the installation of this engine in airplanes is clearly shown at ,figs4 #aej and #aea1 the former having the radiator installed at the front of the motor and having all exhaust pipes joined to one common discharge funnel1 which deflects the gas over the top plane while the latter has the radiator placed vertically above the motor at the back end and has a direct exhaust gas discharge to the air4 ,illustration3 ,fig4 #aej4 ,,censored ,illustration3 ,fig4 #aea4 ,,censored ,the dimensions of the six-cylinder ,hall-,scott motor which is known as the type ,a-#e #abe ,h4 ,p4 are given at ,fig4 #aeb1 which is an end sectional elevation1 and at ,fig4 #aec1 which is a plan view4 ,the dimensions are given both in inch sizes and the metric equivalents4 ,the appearance of a ,hall-,scott six-cylinder engine installed in a fuselage is given at ,fig4 #aed1 while a diagram showing the location of the engine and the various pipes leading to the auxiliary groups is outlined at ,fig4 #aee4 ,the following instructions for installing the ,hall-,scott power plant are reproduced from the instruction book issued by the maker4 ,operating instructions which are given should enable any good mechanic to make a proper installation and to keep the engine in good running condition4 ,illustration3 ,fig4 #aeb4 ,,censored ,,fuel ,,system ,,installation ,illustration3 ,fig4 #aec4--,plan ,view of ,hall-,scott ,type ,a-#e #abe ,horse-,power ,airplane ,engine1 ,showing ,installation ,dimensions4 ,gasoline giving the best results with this equipment is as follows3 ,gravity #eh-fb deg4 ,baume ,a4 ,initial boiling point--,richmond method--#ajb deg4 ,fahr4 ,sulphur 4#jad4 ,calorimetric bomb test #bjfaj ,b4 ,t4 ,u4 per pound4 ,if the gasoline tank is placed in the fuselage below the level of the carburetor1 a hand pump must be used to maintain air pressure in gas tank to force the gasoline to the carburetor4 ,after starting the engine the small auxiliary air pump upon the engine will maintain sufficient pressure4 ,a-#g;a and ,a-#e;a engines are furnished with a new type auxiliary air pump4 ,this should be frequently oiled and care taken so no grit or sand will enter which might lodge between the valve and its seat1 which would make it fail to operate properly4 ,an air relief valve is furnished with each engine4 ,it should be screwed into the gas tank and properly regulated to maintain the pressure required4 ,this is done by screwing the ratchet on top either up or down4 ,if two tanks are used in a plane one should be installed in each tank4 ,all air pump lines should be carefully gone over quite frequently to ascertain if they are tight4 ,check valves have to be placed in these lines4 ,in some cases the gasoline tank is placed above the engine1 allowing it to drain by gravity to the carburetor4 ,when using this system there should be a drop of not less than two feet from the lowest portion of the gasoline tank to the upper part of the carburetor float chamber4 ,even this height might not be sufficient to maintain the proper volume of gasoline to the carburetor at high speeds4 ,air pressure is advised upon all tanks to insure the proper supply of gasoline4 ,when using gravity feed without air pressure be sure to vent the tank to allow circulation of air4 ,if gravity tank is used and the engine runs satisfactorily at low speeds but cuts out at high speeds the trouble is undoubtedly due to insufficient height of the tank above the carburetor4 ,the tank should be raised or air pressure system used4 ,illustration3 ,fig4 #aed4--,three-,quarter ,view of ,hall-,scott ,type ,a-#e #abe ,horse-,power ,six-,cylinder ,engine1 with ,one of the ,side ,radiators ,removed to ,show ,installation in ,standard ,fuselage4 ,illustration3 ,fig4 #aee4--;,diagram ,showing ,proper ,installation of ,hall-,scott ,type ,a-#e #abe ,horse-,power ,engine with ,pressure ,feed ,fuel ,supply ,system4 ,,ignition ,,switches ,two ,,dixie switches are furnished with each engine4 ,both of these should be installed in the pilot's seat1 one controlling the ,r4 ,h41 and the other the ,l4 ,h4 magneto4 ,by shorting either one or the other it can be quickly determined if both magnetos1 with their respective spark-plugs1 are working correctly4 ,care should be taken not to use spark-plugs having special extensions or long protruding points4 ,plugs giving best results are extremely small with short points4 ,,water ,,systems ,a temperature gauge should be installed in the water pipe1 coming directly from the cylinder nearest the propeller 7note illustration above74 ,this instrument installed in the radiator cap has not always given satisfactory results4 ,this is especially noticeable when the water in the radiator becomes low1 not allowing it to touch the bulb on the moto-meter4 ,for ordinary running1 it should not indicate over #aej degrees ,fahr4 ,in climbing tests1 however1 a temperature of #afj degrees ,fahr4 can be maintained without any ill effects upon the engine4 ,in case the engine becomes overheated1 the indicator will register above #ahj degrees ,fahr41 in which case it should be stopped immediately4 ,overheating is most generally caused by retarded spark1 excessive carbon in the cylinders1 insufficient lubrication1 improperly timed valves1 lack of water1 clogging of water system in any way which would obstruct the free circulation of the water4 ,overheating will cause the engine to knock1 with possible damaging results4 ,suction pipes should be made out of thin tubing1 and run within a quarter or an eighth of an inch of each other1 so that when a hose is placed over the two1 it will not be possible to suck together4 ,this is often the case when a long rubber hose is used1 which causes overheating4 ,radiators should be flushed out and cleaned thoroughly quite often4 ,a dirty radiator may cause overheating4 ,when filling the radiator it is very important to remove the plug on top of the water pump until water appears4 ,this is to avoid air pockets being formed in the circulating system1 which might not only heat up the engine1 but cause considerable damage4 ,all water pump hoses and connections should be tightly taped and shellacked after the engine is properly installed in the plane4 ,the greatest care should be taken when making engine installation not to use smaller inside diameter hose connection than water pump suction end casting4 ,one inch and a quarter inside diameter should be used on ,a-#g and ,a-#e motors1 while nothing less than one inch and a half inside diameter hose or tubing on all ,a-#g;a and ,a-#e;a engines4 ,it is further important to have light spun tubing1 void of any sharp turns1 leads from pump to radiator and cylinder water outlet to radiator4 ,in other words1 the water circulation through the engine must be as little restricted as possible4 ,be sure no light hose is used1 that will often suck together when engine is started4 ,to thoroughly drain the water from the entire system1 open the drain cock at the lowest side of the water pump4 ,,preparations ,,to ,,start ,,engine ,always replenish gasoline tanks through a strainer which is clean4 ,this strainer must catch all water and other impurities in the gasoline4 ,pour at least three gallons of fresh oil into the lower crank-case4 ,oil all rocker arms through oilers upon rocker arm housing caps4 ,be sure radiators are filled within one inch of the top4 ,after all the parts are oiled1 and the tanks filled1 the following must be looked after before starting3 ,see if crank-shaft flange is tight on shaft4 ,see if propeller bolts are tight and evenly drawn up4 ,see if propeller bolts are wired4 ,see if propeller is trued up to within #a_/h4 ,every four days the magnetos should be oiled if the engine is in daily use4 ,every month all cylinder hold-down nuts should be gone over to ascertain if they are tight4 7,be sure to recotter nuts47 ,see if magnetos are bolted on tight and wired4 ,see if magneto cables are in good condition4 ,see if rocker arm tappets have a 4#jbj clearance from valve stem when valve is seated4 ,see if tappet clamp screws are tight and cottered4 ,see if all gasoline1 oil1 water pipes and connections are in perfect condition4 ,air on gas line should be tested for leaks4 ,pump at least three pounds air pressure into gasoline tank4 ,after making sure that above rules have been observed1 test compression of cylinders by turning propeller4 ,,do ,,not ,,forget ,,to ,,short ,,both ,,magnetos ,be sure all compression release and priming cocks do not leak compression4 ,if they do1 replace same with a new one immediately1 as this might cause premature firing4 ,open priming cocks and squirt some gasoline into each4 ,close cocks4 ,open compression release cocks4 ,open throttle slightly4 ,if using ,berling magnetos they should be three-quarters advanced4 ,if all the foregoing directions have been carefully followed1 the engine is ready for starting4 ,in cranking engine either by starting crank1 or propeller1 it is essential to throw it over compression quickly4 ,immediately upon starting1 close compression release cocks4 ,when engine is running1 advance magnetos4 ,after it has warmed up1 short one magneto and then the other1 to be sure both magnetos and spark-plugs are firing properly4 ,if there is a miss1 the fouled plug must be located and cleaned4 ,there is a possibility that the jets in the carburetor are stopped up4 ,if this is the case1 do not attempt to clean same with any sharp instrument4 ,if this is done1 it might change the opening in the jets1 thus spoiling the adjustment4 ,jets and nozzles should be blown out with air or steam4 ,an open intake or exhaust valve1 which might have become sluggish or stuck from carbon1 might cause trouble4 ,be sure to remedy this at once by using a little coal-oil or kerosene on same1 working the valve by hand until it becomes free4 ,we recommend using graphite on valve stems mixed with oil to guard against sticking or undue wear4 ,,installing ,,rotary ,,and ,,radial ,,cylinder ,,engines ,illustration3 ,fig4 #aef4--;,diagram ,defining ,installation of ,gnome ,monosoupape ,motor in ,tractor ,biplane4 ,note ,necessary ,piping for ,fuel1 ,oil1 and ,air ,lines4 ,when rotary engines are installed simple steel stamping or spiders1 are attached to the fuselage to hold the fixed crank-shaft4 ,inasmuch as the motor projects clear of the fuselage proper there is plenty of room back of the front spider plate to install the auxiliary parts such as the oil pump1 air pump and ignition magneto and also the fuel and oil containers4 ,the diagram given at ,fig4 #aef shows how a ,gnome monosoupape engine is installed on the anchorage plates and it also outlines clearly the piping necessary to convey the oil and fuel and also the air-piping needed to put pressure on both fuel and oil tanks to insure positive supply of these liquids which may be carried in tanks placed lower than the motor in some installations4 ,the diagram given at ,figs4 #aeg and #aeh shows other mountings of ,gnome engines and are self-explanatory4 ,the simple mounting possible when the ,anzani ten-cylinder radial fixed type engine is used given at ,fig4 #aei4 ,the front end of the fuselage is provided with a substantial pressed steel plate having members projecting from it which may be bolted to the longerons4 ,the bolts that hold the two halves of the crank-case together project through the steel plate and hold the engine securely to the front end of the fuselage4 ,illustration3 ,fig4 #aeg4--,showing ,two ,methods of ,placing ,propeller on ,gnome ,rotary ,motor4 ,,practical ,,hints ,,to ,,locate ,,engine ,,troubles ,illustration3 ,fig4 #aeh4--;,how ,gnome ,rotary ,motor ,may ,be ,attached to ,airplane ,fuselage ,members4 ,one who is not thoroughly familiar with engine construction will seldom locate troubles by haphazard experimenting and it is only by a systematic search that the cause can be discovered and the defects eliminated4 ,in this chapter the writer proposes to outline some of the most common power-plant troubles and to give sufficient advice to enable those who are not thoroughly informed to locate them by a logical process of elimination4 ,the internal-combustion motor1 which is the power plant of all gasoline automobiles as well as airplanes1 is composed of a number of distinct groups1 which in turn include distinct components4 ,these various appliances are so closely related to each other that defective action of any one may interrupt the operation of the entire power plant4 ,some of the auxiliary groups are more necessary than others and the power plant will continue to operate for a time even after the failure of some important parts of some of the auxiliary groups4 ,the gasoline engine in itself is a complete mechanism1 but it is evident that it cannot deliver any power without some means of supplying gas to the cylinders and igniting the compressed gas charge after it has been compressed in the cylinders4 ,from this it is patent that the ignition and carburetion systems are just as essential parts of the power plant as the piston1 connecting rod1 or cylinder of the motor4 ,the failure of either the carburetor or igniting means to function properly will be immediately apparent by faulty action of the power plant4 ,illustration3 ,fig4 #aei4--;,how ,anzani ,ten-,cylinder ,radial ,engine is ,installed to ,plate ,securely ,attached to ,front ,end of ,tractor ,airplane ,fuselage4 ,to insure that the motor will continue to operate it is necessary to keep it from overheating by some form of cooling system and to supply oil to the moving parts to reduce friction4 ,the cooling and lubrication groups are not so important as carburetion and ignition1 as the engine would run for a limited period of time even should the cooling system fail or the oil supply cease4 ,it would only be a few moments1 however1 before the engine would overheat if the cooling system was at fault1 and the parts seize if the lubricating system should fail4 ,any derangement in the carburetor or ignition mechanism would manifest itself at once because the engine operation would be affected1 but a defect in the cooling or oiling system would not be noticed so readily4 ,the careful aviator will always inspect the motor mechanism before starting on a trip of any consequence1 and if inspection is carefully carried out and loose parts tightened it is seldom that irregular operation will be found due to actual breakage of any of the components of the mechanism4 ,deterioration due to natural causes matures slowly1 and sufficient warning is always given when parts begin to wear so satisfactory repairs may be promptly made before serious derangement or failure is manifested4 ,a ,,typical ,,engine ,,stoppage ,,analyzed ,before describing the points that may fail in the various auxiliary systems it will be well to assume a typical case of engine failure and show the process of locating the trouble in a systematic manner by indicating the various steps which are in logical order and which could reasonably be followed4 ,in any case of engine failure the ignition system1 motor compression1 and carburetor should be tested first4 ,if the ignition system is functioning properly one should determine the amount of compression in all cylinders and if this is satisfactory the carbureting group should be tested4 ,if the ignition system is working properly and there is a decided resistance in the cylinders when the propeller is turned1 proving that there is good compression1 one may suspect the carburetor4 ,illustration3 ,fig4 #afj4--,side ,elevation of ,thomas #ace ,horse-,power ,airplane ,engine1 ,giving ,important ,dimensions4 ,if the carburetor appears to be in good condition1 the trouble may be caused by the ignition being out of time1 which condition is possible when the magneto timing gear or coupling is attached to the armature shaft by a taper and nut retention instead of the more positive key or taper-pin fastening4 ,it is possible that the inlet manifold may be broken or perforated1 that the exhaust valve is stuck on its seat because of a broken or bent stem1 broken or loose cam1 or failure of the cam-shaft drive because the teeth are stripped from the engine shaft or cam-shaft gears2 or because the key or other fastening on either gear has failed1 allowing that member to turn independently of the shaft to which it normally is attached4 ,the gasoline feed pipe may be clogged or broken1 the fuel supply may be depleted1 or the shut-off cock in the gasoline line may have jarred closed4 ,the gasoline filter may be filled with dirt or water which prevents passage of the fuel4 ,illustration3 ,fig4 #afa4--;,front ,elevation of ,thomas-,morse #ace ,horse-,power ,aeromotor1 ,showing ,main ,dimensions4 ,the defects outlined above1 except the failure of the gasoline supply1 are very rare1 and if the container is found to contain fuel and the pipe line to be clear to the carburetor1 it is safe to assume the vaporizing device is at fault4 ,if fuel continually runs out of the mixing chamber the carburetor is said to be flooded4 ,this condition results from failure of the shut-off needle to seat properly or from a punctured hollow metal float or a gasoline-soaked cork float4 ,it is possible that not enough gasoline is present in the float chamber4 ,if the passage controlled by the float-needle valve is clogged or if the float was badly out of adjustment1 this contingency would be probable4 ,when the carburetor is examined1 if the gasoline level appears to be at the proper height1 one may suspect that a particle of lint1 or dust1 or fine scale1 or rust from the gasoline tank has clogged the bore of the jet in the mixing chamber4 ,if the ignition system and carburetor appear to be in good working order1 and the hand crank shows that there is no compression in one or more of the cylinders1 it means some defect in the valve system4 ,if the engine is a multiple-cylinder type and one finds poor compression in all of the cylinders it may be due to the rare defect of improper valve timing4 ,this may be caused by a gear having altered its position on the cam-shaft or crank-shaft1 because of a sheared key or pin having permitted the gear to turn about half of a revolution and then having caught and held the gear in place by a broken or jagged end so that cam-shaft would turn1 but the valves open at the wrong time4 ,if but one of the cylinders is at fault and the rest appear to have good compression the trouble may be due to a defective condition either inside or outside of that cylinder4 ,the external parts may be inspected easily1 so the following should be looked for3 a broken valve1 a warped valve-head1 broken valve-springs1 sticking or bent valve-stems1 dirt under valve-seat1 leak at valve-chamber cap or spark-plug gasket4 ,defective priming cock1 cracked cylinder head 7rarely occurs71 leak through cracked spark-plug insulation1 valve-plunger stuck in the guide1 lack of clearance between valve-stem end and top of plunger caused by loose adjusting screw which has worked up and kept the valve from seating4 ,the faulty compression may be due to defects inside the motor4 ,the piston-head may be cracked 7rarely occurs71 piston rings may be broken1 the slots in the piston rings may be in line1 the rings may have lost their elasticity or have become gummed in the grooves of the piston1 or the piston and cylinder walls may be badly scored by a loose wrist pin or by defective lubrication4 ,if the motor is a type with a separate head it is possible the gasket or packing between the cylinder and combustion chamber may leak1 either admitting water to the cylinder or allowing compression to escape4 ,illustration3 ,fig4 #afb4--;,front and ,side ,elevations of ,sturtevant ,airplane ,engine1 ,giving ,principal ,dimensions to ,facilitate ,installation4 ,,conditions ,,that ,,cause ,,failure ,,of ,,ignition ,,system ,if the first test of the motor had showed that the compression was as it should be and that there were no serious mechanical defects and there was plenty of gasoline at the carburetor1 this would have demonstrated that the ignition system was not functioning properly4 ,if a battery is employed to supply current the first step is to take the spark-plugs out of the cylinders and test the system by turning over the engine by hand4 ,if there is no spark in any of the plugs1 this may be considered a positive indication that there is a broken main current lead from the battery1 a defective ground connection1 a loose battery terminal1 or a broken connector4 ,if none of these conditions are present1 it is safe to say that the battery is no longer capable of delivering current4 ,while magneto ignition is generally used on airplane engines1 there is apt to be some development of battery ignition1 especially on engines equipped with electric self-starters which are now being experimented with4 ,the spark-plugs may be short circuited by cracked insulation or carbon and oil deposits around the electrode4 ,the secondary wires may be broken or have defective insulation which permits the current to ground to some metal part of the fuselage or motor4 ,the electrodes of the spark-plug may be too far apart to permit a spark to overcome the resistance of the compressed gas1 even if a spark jumps the air space1 when the plug is laid on the cylinder4 ,if magnetos are fitted as is usually the case at present and a spark is obtained between the points of the plug and that device or the wire leading to it from the magneto is in proper condition1 the trouble is probably caused by the magneto being out of time4 ,this may result if the driving gear is loose on the armature-shaft or crank-shaft1 and is a rare occurrence4 ,if no spark is produced at the plugs the secondary wire may be broken1 the ground wire may make contact with some metallic portion of the chassis before it reaches the switch1 the carbon collecting brushes may be broken or not making contact1 the contact points of the make-and-break device may be out of adjustment1 the wiring may be attached to wrong terminals1 the distributor filled with metallic particles1 carbon1 dust or oil accumulations1 the distributor contacts may not be making proper connection because of wear and there may be a more serious derangement1 such as a burned out secondary winding or a punctured condenser4 ,if the motor runs intermittently1 i4e41 starts and runs only a few revolutions1 aside from the conditions previously outlined1 defective operation may be due to seizing between parts because of insufficient oil or deficient cooling1 too much oil in the crank-case which fouls the cylinder after the crank-shaft has revolved a few turns1 and derangements in the ignition or carburetion systems that may be easily remedied4 ,there are a number of defective conditions which may exist in the ignition group1 that will result in skipping or irregular operation and the following points should be considered first3 weak source of current due to worn out dry cells or discharged storage batteries2 weak magnets in magneto1 or defective contacts at magneto2 dirt in magneto distributor or poor contact at collecting brushes4 ,dirty or cracked insulator at spark-plug will cause short circuit and can only be detected by careful examination4 ,the following points should also be checked over when the plug is inspected3 ,excessive space between electrodes1 points too close together1 loose central electrodes1 or loose point on plug body1 soot or oil particles between electrodes1 or on the surface of the insulator1 cracked insulator1 oil or water on outside of insulator4 ,short circuits in the condenser or internal wiring of induction coils or magnetos1 which are fortunately not common1 can seldom be remedied except at the factory where these devices were made4 ,if an engine stops suddenly and the defect is in the ignition system the trouble is usually never more serious than a broken or loose wire4 ,this may be easily located by inspecting the wiring at the terminals4 ,irregular operation or misfiring is harder to locate because the trouble can only be found after the many possible defective conditions have been checked over1 one by one4 ,,common ,,defects ,,in ,,fuel ,,systems ,defective carburetion often causes misfiring or irregular operation4 ,the common derangement of the components of the fuel system that are common enough to warrant suspicion and the best methods for their location follows3 ,first1 disconnect the feed pipe from the carburetor and see if the gasoline flows freely from the tank4 ,if the stream coming out of the pipe is not the full size of the orifice it is an indication that the pipe is clogged with dirt or that there is an accumulation of rust1 scale1 or lint in the strainer screens of the filter4 ,it is also possible that the fuel shut-off valve may be wholly or partly closed4 ,if the gasoline flows by gravity the liquid may be air bound in the tank1 while if a pressure-feed system is utilized the tank may leak so that it does not retain pressure2 the check valve retaining the pressure may be defective or the pipe conveying the air or gas under pressure to the tank may be clogged4 ,if the gasoline flows from the pipe in a steady stream the carburetor demands examination4 ,there may be dirt or water in the float chamber1 which will constrict the passage between the float chamber and the spray nozzle1 or a particle of foreign matter may have entered the nozzle and stopped up the fine holes therein4 ,the float may bind on its guide1 the needle valve regulating the gasoline-inlet opening in bowl may stick to its seat4 ,any of the conditions mentioned would cut down the gasoline supply and the engine would not receive sufficient quantities of gas4 ,the air-valve spring may be weak or the air valve broken4 ,the gasoline-adjusting needle may be loose and jar out of adjustment1 or the air-valve spring-adjusting nuts may be such a poor fit on the stem that adjustments will not be retained4 ,these instructions apply only to carburetors having air valves and mixture regulating means which are used only in rare instances in airplane work4 ,air may leak in through the manifold1 due to a porous casting1 or leaky joints in a built up form and dilute the mixture4 ,the air-intake dust screen may be so clogged with dirt and lint that not enough air will pass through the mesh4 ,water or sediment in the gasoline will cause misfiring because the fuel feed varies when the water or dirt constricts the standpipe bore4 ,it is possible that the carburetor may be out of adjustment4 ,if clouds of black smoke are emitted at the exhaust pipe it is positive indication that too much gasoline is being supplied the mixture and the supply should be cut down by screwing in the needle valve on types where this method of regulation is provided1 and by making sure that the fuel level is at the proper height1 or that the proper nozzle is used in those forms where the spray nozzle has no means of adjustment4 ,if the mixture contains too much air there will be a pronounced popping back in the carburetor4 ,this may be overcome by screwing in the air-valve adjustment so the spring tension is increased or by slightly opening up the gasoline-supply regulation needle4 ,when a carburetor is properly adjusted and the mixture delivered the cylinder burns properly1 the exhaust gas will be clean and free from the objectionable odor present when gasoline is burned in excess4 ,the character of combustion may be judged by the color of the flame which issues from it when the engine is running with an open throttle after nightfall4 ,if the flame is red1 it indicates too much gasoline4 ,if yellowish1 it shows an excess of air1 while a properly proportioned mixture will be evidenced by a pronounced blue flame1 such as given by a gas-stove burner4 ,the ,duplex ,model ,o4 ,d4 ,zenith carburetor used upon most of the six- and eight-cylinder airplane engines consists of a single float chamber1 and a single air intake1 joined to two separate and distinct spray nozzles1 venturi and idling adjustments4 ,it is to be noted that as the carburetor barrels are arranged side by side1 both valves are mounted on the same shaft1 and work in unison through a single operating lever4 ,it is not necessary to alter their position4 ,in order to make the engine idle well1 it is essential that the ignition1 especially the spark-plugs1 should be in good condition4 ,the gaskets between carburetor and manifold1 and between manifold and cylinders should be absolutely air-tight4 ,the adjustment for low speed on the carburetor is made by turning in or out the two knurled screws1 placed one on each side of the float chamber4 ,after starting the engine and allowing it to become thoroughly warmed1 one side of the carburetor should be adjusted so that the three cylinders it affects fire properly at low speed4 ,the other side should be adjusted in the same manner until all six cylinders fire perfectly at low speed4 ,as the adjustment is changed on the knurled screw a difference in the idling of the engine should be noticed4 ,if the engine begins to run evenly or speeds up it shows that the mixture becomes right in its proportion4 ,be sure the butterfly throttle is closed as far as possible by screwing out the stop screw which regulates the closed position for idling4 ,care should be taken to have the butterfly held firmly against this stop screw at all times while idling engine4 ,if three cylinders seem to run irregularly after changing the position of the butterfly1 still another adjustment may have to be made with the knurled screw4 ,unscrewing this makes the mixture leaner4 ,screwing in closes off some of the air supply to the idling jet1 making it richer4 ,after one side has been made to idle satisfactorily repeat the same procedure with the opposite three cylinders4 ,in other words1 each side should be idled independently to about the same speed4 ,remember that the main jet and compensating jet have no appreciable effect on the idling of the engine4 ,the idling mixture is drawn directly through the opening determined by the knurled screw and enters the carburetor barrel through the small hole at the edge of each butterfly4 ,this is called the priming hole and is only effective during idling4 ,beyond that point the suction is transferred to the main jet and compensator1 which controls the power of the engine beyond the idling position of the throttle4 ,,defects ,,in ,,oiling ,,systems ,while troubles existing in the ignition or carburetion groups are usually denoted by imperfect operation of the motor1 such as lost power1 and misfiring1 derangements of the lubrication or cooling systems are usually evident by overheating1 diminution in engine capacity1 or noisy operation4 ,overheating may be caused by poor carburetion as much as by deficient cooling or insufficient oiling4 ,when the oiling group is not functioning as it should the friction between the motor parts produces heat4 ,if the cooling system is in proper condition1 as will be evidenced by the condition of the water in the radiator1 and the carburetion group appears to be in good condition1 the overheating is probably caused by some defect in the oiling system4 ,the conditions that most commonly result in poor lubrication are3 ,insufficient oil in the engine crank-case or sump1 broken or clogged oil pipes1 screen at filter filled with lint or dirt1 broken oil pump1 or defective oil-pump drive4 ,the supply of oil may be reduced by a defective inlet or discharge-check valve at the mechanical oiler or worn pumps4 ,a clogged oil passage or pipe leading to an important bearing point will cause trouble because the oil cannot get between the working surfaces4 ,it is well to remember that much of the trouble caused by defective oiling may be prevented by using only the best grades of lubricant1 and even if all parts of the oil system are working properly1 oils of poor quality will cause friction and overheating4 ,,defects ,,in ,,cooling ,,systems ,,outlined ,cooling systems are very simple and are not liable to give trouble as a rule if the radiator is kept full of clean water and the circulation is not impeded4 ,when overheating is due to defective cooling the most common troubles are those that impede water circulation4 ,if the radiator is clogged or the piping of water jackets filled with rust or sediment the speed of water circulation will be slow1 which will also be the case if the water pump or its driving means fail4 ,any scale or sediment in the water jackets or in the piping or radiator passages will reduce the heat conductivity of the metal exposed to the air1 and the water will not be cooled as quickly as though the scale was not present4 ,the rubber hose often used in making the flexible connections demanded between the radiator and water manifolds of the engine may deteriorate inside and particles of rubber hang down that will reduce the area of the passage4 ,the grease from the grease cups mounted on the pump-shaft bearing to lubricate that member often finds its way into the water system and rots the inner walls of the rubber hose1 this resulting in strips of the partly decomposed rubber lining hanging down and restricting the passage4 ,the cooling system is prone to overheat after antifreezing solutions of which calcium chloride forms a part have been used4 ,this is due to the formation of crystals of salt in the radiator passages or water jackets1 and these crystals can only be dissolved by suitable chemical means1 or removed by scraping when the construction permits4 ,overheating is often caused by some condition in the fuel system that produces too rich or too lean mixture4 ,excess gasoline may be supplied if any of the following conditions are present3 ,bore of spray nozzle or standpipe too large1 auxiliary air-valve spring too tight1 gasoline level too high1 loose regulating valve1 fuel-soaked cork float1 punctured sheet-metal float1 dirt under float control shut-off valve or insufficient air supply because of a clogged air screen4 ,if pressure feed is utilized there may be too much pressure in the tank1 or the float controlled mechanism operating the shut-off in the float bowl of the carburetor may not act quickly enough4 ,,some ,,causes ,,of ,,noisy ,,operation ,there are a number of power-plant derangements which give positive indication because of noisy operation4 ,any knocking or rattling sounds are usually produced by wear in connecting rods or main bearings of the engine1 though sometimes a sharp metallic knock1 which is very much the same as that produced by a loose bearing1 is due to carbon deposits in the cylinder heads1 or premature ignition due to advanced spark-time lever4 ,squeaking sounds invariably indicate dry bearings1 and whenever such a sound is heard it should be immediately located and oil applied to the parts thus denoting their dry condition4 ,whistling or blowing sounds are produced by leaks1 either in the engine itself or in the gas manifolds4 ,a sharp whistle denotes the escape of gas under pressure and is usually caused by a defective packing or gasket that seals a portion of the combustion chamber or that is used for a joint as the exhaust manifold4 ,a blowing sound indicates a leaky packing in crank-case4 ,grinding noises in the motor are usually caused by the timing gears and will obtain if these gears are dry or if they have become worn4 ,whenever a loud knocking sound is heard careful inspection should be made to locate the cause of the trouble4 ,much harm may be done in a few minutes if the engine is run with loose connecting rod or bearings that would be prevented by taking up the wear or looseness between the parts by some means of adjustment4 ,,brief ,,summary ,,of ,,hints ,,for ,,starting ,,engine ,first make sure that all cylinders have compression4 ,to ascertain this1 open pet cocks of all cylinders except the one to be tested1 crank over motor and see that a strong opposition to cranking is met with once in two revolutions4 ,if motor has no pet cocks1 crank and notice that oppositions are met at equal distances1 two to every revolution of the starting crank in a four-cylinder motor4 ,if compression is lacking1 examine the parts of the cylinder or cylinders at fault in the following order1 trying to start the motor whenever any one fault is found and remedied4 ,see that the valve push rods or rocker arms do not touch valve stems for more than approximately #a_/b revolution in every #b revolutions1 and that there is not more than 4#jaj to 4#jbj inch clearance between them depending on the make of the motor4 ,make sure that the exhaust valve seats4 ,to determine this examine the spring and see that it is connected to the valve stem properly4 ,take out valve and see that there is no obstruction1 such as carbon1 on its seat4 ,see that valve works freely in its guide4 ,examine inlet valve in same manner4 ,listen for hissing sound while cranking motor for leaks at other places4 ,make sure that a spark occurs in each cylinder as follows3 ,if magneto or magneto and battery with non-vibrating coil is used3 ,disconnect wire from spark-plug1 hold end about #a_/h inch from cylinder or terminal of spark-plug4 ,have motor cranked briskly and see if spark occurs4 ,examine adjustment of interrupter points4 ,see that wires are placed correctly and not short circuited4 ,take out spark-plug and lay it on the cylinder1 being careful that base of plug only touches the cylinder and that ignition wire is connected4 ,have motor cranked briskly and see if spark occurs4 ,check timing of magneto and see that all brushes are making contact4 ,see if there is gasoline in the carburetor4 ,see that there is gasoline in the tank4 ,examine valve at tank4 ,prime carburetor and see that spray nozzle passage is clear4 ,be sure throttle is open4 ,prime cylinders by putting about a teaspoonful of gasoline in through pet cock or spark-plug opening4 ,adjust carburetor if necessary4 ,,location ,,of ,,engine ,,troubles ,,made ,,easy ,the following tabulation has been prepared and originated by the writer to outline in a simple manner the various troubles and derangements that interfere with efficient internal-combustion engine action4 ,the parts and their functions are practically the same in all gas or gasoline engines of the four-cycle type1 and the general instructions given apply just as well to all hydro-carbon engines1 even if the parts differ in form materially4 ,the essential components are clearly indicated in the many part sectional drawings in this book so they may be easily recognized4 ,the various defects that may materialize are tabulated in a manner that makes for ready reference1 and the various defective conditions are found opposite the part affected1 and under a heading that denotes the main trouble to which the others are contributing causes4 ,the various symptoms denoting the individual troubles outlined are given to facilitate their recognition in a positive manner4 ,brief note is also made of the remedies for the restoration of the defective part or condition4 ,it is apparent that a table of this character is intended merely as a guide1 and it is a compilation of practically all the known troubles that may materialize in gas-engine operation4 ,while most of the defects outlined are common enough to warrant suspicion1 they will never exist in an engine all at the same time1 and it will be necessary to make a systematic search for such of those as exist4 ,to use the list advantageously1 it is necessary to know one main trouble easily recognized4 ,for example1 if the power plant is noisy1 look for the possible troubles under the head of ,noisy ,operation2 if it lacks capacity1 the derangement will undoubtedly be found under the head of ,lost ,power4 ,it is assumed in all cases that the trouble exists in the power plant or its components1 and not in the auxiliary members of the ignition1 carburetion1 lubrication1 or cooling systems4 ,the novice and student will readily recognize the parts of the average aviation engine by referring to the very complete and clearly lettered illustrations of mechanism given in many parts of this treatise4 ,,lost ,,power ,,and ,,overheating ---------------------------------------- ---------------------------------- ,,part ,,affected ,,nature ,,of ,,trouble ,,symptoms ,,and ,,remedy ,,effects ---------------------------------------- ---------------------------------- ,water ,pipe ,joint4 ,loose4 ,loss of water1 ,tighten bolts1 heating4 replace gaskets4 ,spark ,plug4 ,leakage in ,loss of power4 ,replace insulation threads1 ,hissing caused by if defective1 screw insulation1 escaping gas4 down tighter4 packing4 ,compression ,leak in threads4 ,loss of power4 ,tighten if loose4 ,release ,cock4 ,leak in fitting4 ,whistling or ,grind fitting to hissing4 new seating in body4 ,combustion ,crack or blowhole4,loss of compres- ,fill by welding4 ,chamber4 ,roughness4 ,carbon sion4 ,preignition4,smooth out deposits4 ,sharp roughness4 ,scrape edges4 out or dissolve carbon4 ,valve ,chamber ,cap4,leak in threads4 ,loss of compres- ,remove4 ,apply pipe ,defective gasket4 sion4 ,hissing4 compound to threads and replace4 ,use new gasket or packing4 ,valve ,head4 ,warped4 ,scored or ,loss of compres- ,true up in lathe4 pitted4 ,carbon- sion4 ,grind to seat4 ized4 ,covered with ,scrape off4 ,smooth scale4 ,loose on with emery cloth4 stem 7two-piece ,tighten by valves only74 riveting4 ,valve ,seat4 ,warped or pitted4 ,loss of compres- ,use reseating ,covered with car- sion4 reamer4 ,clean off bon4 ,foreign mat- and grind valve to ter between valve seat4 and seat4 ,valve ,stem4 ,covered with ,valve does not ,clean with emery scale4 ,bent4 ,bind-close4 ,loss of cloth2 straighten4 ing in guide4 compression4 ,true up and smooth ,stuck in guide4 off4 free with kerosene4 ,valve ,stem ,guide4 ,burnt or rough4 ,valve may stick4 ,clean out hole4 ,loose in valve ,action irregular4 ,screw in tighter4 chamber4 ,valve ,spring4 ,weak or broken4 ,valve does not close4 ,valve ,operating ,loose in guide4 ,valve action poor4,replace with new4 ,plunger4 ,too much clearance,lift insufficient4,adjust screw closer4 between valve stem4 ,valve ,lift ,ad- ,threads stripped4 ,poor valve action4,replace with new4 justing ,screw4 ,too near valve4 ,adjust with proper ,too far from reference to valve valve4 stem4 ,valve ,lift ,cam4 ,worn cam contour4 ,not enough valve ,replace with new4 ,loose on shaft4 lift4 ,will not ,replace pins or ,out of time4 lift valve4 ,valve keys4 ,set to open opens at wrong properly4 time4 ,cam-shaft4 ,sprung or twisted4,valves out of ,straighten4 time4 ,cam-shaft ,bushing4,worn4 ,not enough valve ,replace4 lift4 ,cam-shaft ,drive ,loose on shaft4 ,irregular valve ,fasten securely4 ,gear4 ,out of time4 ,worn action4 ,time properly4 or broken teeth4 ,replace with new4 ,cam ,fastenings4 ,worn or broken4 ,valves out of ,replace with new4 time4 ,cylinder ,wall4 ,scored1 gas leaks4,poor compression4 ,grind out bore4 ,poor lubrication ,overheating4 ,repair oiling causes friction4 system4 ,piston4 ,binds in cylinder4,overheating4 ,poor ,lap off excess ,walls scored4 ,worncompression4 metal4 ,replace with out of round4 new4 ,piston ,rings4 ,loss of spring4 ,loss of compres- ,peen ring or ,loose in grooves4 sion4 ,gas blows replace4 ,fit new ,scored4 ,worn or by4 rings4 ,grind smooth4 broken4 ,slots in ,replace4 ,turn slots line4 apart4 ,carbon in grooves4,overheating be- ,remove deposits4 ,insufficient open-cause of friction4,file slot4 ,grind or ing4 ,binding on lap to fit cylinder cylinder4 bore4 ,wristpin4 ,loose1 scores ,loss of compres- ,fasten securely4 cylinder4 sion4 ,replace cylinder if groove is deep4 ,crank-shaft4 ,scored or rough on,overheating be- ,smooth up4 journals4 ,sprung4 cause of friction4,straighten4 ,crank ,bearings4 ,adjusted too ,overheating be- ,adjust freely1 clean ,main ,bearings4 tight4 ,defective cause of friction4out oil holes and oiling4 ,brasses enlarge oil grooves4 burned4 ,oil ,sump4 ,insufficient oil4 ,overheating4 ,replenish supply4 ,poor lubricant4 ,use best oil4 ,wash ,dirty oil4 out with kerosene2 put in clean oil4 ,water ,space4 ,water,clogged with sedi-,overheating4 ,dissolve foreign ,pipes4 ment or scale4 matter and remove4 ,piston ,head4 ,cracked 7rare74 ,loss of compres- ,weld by autogenous ,carbon deposits4 sion4 ,preignition4process4 ,scrape off carbon accumula- tions4 ---------------------------------------- ---------------------------------- ,,noisy ,,operation ,,of ,,power ,,plant ---------------------------------------- ---------------------------------- ,,part ,,affected ,,nature ,,of ,,trouble ,,character ,,of ,,remedy ,,noise ---------------------------------------- ---------------------------------- ,compression ,re- ,leakage4 ,hissing4 ,previously given4 lease ,cock4 ,spark ,plug4 ,leakage4 ,hissing4 ,previously given4 ,valve ,chamber ,cap4,leakage4 ,hiss or whistle4 ,previously given4 ,combustion ,carbon deposits4 ,knocking4 ,previously given4 ,chamber4 ,inlet ,valve ,seat4 ,defects previously,popping in carbu- ,previously given4 given4 retor4 ,valve ,head4 ,loose on stem4 ,clicking4 ,previously given4 ,valve ,stem4 ,valve ,wear or looseness4,rattle or click- ,previously given4 ,stem ,guide4 ing4 ,inlet ,valve4 ,closes too late4 ,blowback in carbu-,previously given4 ,opens too early4 retor4 ,valve ,spring4 ,weak or broken4 ,blowback in carbu-,previously given4 retor4 ,cylinder ,casting4 ,retaining bolts ,sharp metallic ,tighten bolts4 ,round loose4 ,piston knock4 edges of piston strikes at upper top4 end4 ,cylinder ,wall4 ,scored4 ,hissing4 ,previously given4 ,valve ,stem ,too much4 ,clicking4 ,blowback,previously given4 ,clearance4 ,too little 7inlet in carburetor4 valve74 ,valve ,operating ,looseness4 ,rattle or click- ,previously given4 ,plunger4 ,plunger ing4 ,guide4 ,timing ,gears4 ,loose on fasten- ,metallic knock4 ,previously given4 ings4 ,worn teeth4 ,rattle4 ,grinding4 ,cylinder or ,no oil1 or poor ,grinding4 ,repair oil system4 ,piston4 lubricant4 ,cam4 ,loose on shaft4 ,metallic knock4 ,previously given4 ,worn contour4 ,cam-shaft ,bearing4,looseness or wear4,slight knock4 ,previously given4 ,cam ,fastening4 ,looseness4 ,clicking4 ,previously given4 ,piston4 ,binding in cylin- ,grinding or dull ,previously given4 der4 ,worn oval1 squeak4 ,dull causes side slap hammering4 in cylinder4 ,piston ,head4 ,carbon deposits4 ,knocking4 ,previously given4 ,piston ,rings4 ,defective oiling4 ,squeaking4 ,hiss- ,previously given4 ,leakage4 ,binding ing4 ,grinding4 in cylinder4 ,wrist-pin4 ,loose in piston4 ,dull metallic ,replace with new ,worn4 knock4 member4 ,connecting ,rod4 ,wear in upper ,distinct knock4 ,adjust or replace4 bushing4 ,wear at ,scrape and fit4 ,use crank-pin4 ,side longer wrist-pin play in piston4 bushing4 ,crank ,bearings4 ,looseness4 ,exces- ,metallic knock4 ,refit bearings4 sive end play4 ,intermittent ,longer bushings ,binding1 fitted knock4 ,squeaking4 needed4 ,insert shims too tight4 to allow more play4 ,main ,bearings4 ,looseness4 ,defec- ,metallic knock4 ,fit brasses closer tive lubrication4 ,squeaking4 to shaft4 ,clean out oil holes and grooves4 ,connecting ,rod ,loose4 ,sharp knock4 ,tighten4 ,bolts4 ,main ,bearing ,bolts4 ,crank-shaft4 ,defective oiling4 ,squeaking4 ,previously given4 ,engine ,base4 ,loose on frame4 ,sharp pounding4 ,tighten bolts4 ,lower ,half ,crank- ,bolts loose4 ,knocking4 ,tighten bolts4 case4 ,fly-wheel4 ,loose on crank- ,very sharp knock4 ,tighten retention shaft4 bolts or fit new keys4 ,oil ,sump4 ,oil level too low4,grinding and ,replenish with best ,poor lubricant4 squeak in all cylinder oil4 bearings4 ,valve ,plunger ,re- ,looseness4 ,clicking4 ,tighten nuts4 tention ,stirrups4 ,fan4 ,blade loose4 ,blade,clicking or ,tighten4 ,bend back4 strikes cooler4 rattle4 ,exhaust ,pipe ,leakage4 ,sharp hissing4 ,tighten or use new ,joints4 gasket4 ,crank-case ,leakage4 ,blowing sound4 ,use new packing4 ,packing4 ,tighten bolts4 ,water ,pipe4 ,leaks4 ,loss of ,pounding because ,previously given4 water4 ,clogged engine heats4 with sediment4 ,water ,jacket4 ,clogged with sedi-,knocking because ,dissolve scale and ment4 ,walls engine heats4 flush out water covered with space with water scale4 under pressure4 ---------------------------------------- ------------------------------------ ,,skipping ,,or ,,irregular ,,operation ---------------------------------------- ---------------------------------- ,,part ,,affected ,,nature ,,of ,,trouble ,,symptoms ,,and ,,remedy ,,effects ---------------------------------------- ---------------------------------- ,compression ,relief,leak in threads or,dilutes mixture ,screw down tighter4 ,cock4 spigot4 with air1 causes ,grind spigot to seat blowback4 with emery4 ,spark-,plug4 ,leak in threads4 ,dilutes mixture4 ,screw down tighter4 ,defective gasket4 ,allows short ,replace with new4 ,cracked insulator4circuit4 ,no spark4,set points #a_/fd ,points too near4 apart for magneto1 ,points covered #a_/cb for battery with carbon4 ,too spark4 much air gap4 ,valve ,chamber ,cap4,leak in threads4 ,dilutes mixture by,previously given4 ,defective gasket4 allowing air to enter cylinder on suction stroke4 ,combustion ,carbon deposits4 ,preignition4 ,scrape out4 ,chamber4 ,valve ,head4 ,warped or pitted4 ,dilutes charge ,previously given4 ,loose on stem4 with poor air or gas4 ,valve ,stem4 ,binding in guide4 ,irregular valve ,previously given4 ,sticking4 action4 ,valve ,seat4 ,scored or warped4 ,gas leak1 poor ,previously given4 ,cracked4 ,covered mixture4 ,poor com- with scale4 ,dirt pression4 ,valve under valve4 will not close4 ,induction ,pipe4 ,leak at joints4 ,mixture diluted ,stop all leaks4 ,crack or blowhole4with excess air4 ,inlet ,valve4 ,closes too late4 ,blowback in carbu-,time properly4 ,opens too early4 retor4 ,exhaust ,valve4 ,opens too late4 ,retention of burnt,time properly4 ,closes too early4 gas dilutes charge4 ,valve ,stem ,guide4 ,bent or carbon- ,causes valve to ,previously given4 ized4 stick4 ,inlet ,valve ,stem ,worn1 stem loose4 ,air drawn in on ,bush guide or use ,guide4 suction thins gas4new member4 ,valve ,spring4 ,weakened or ,irregular action4 ,use new spring4 broken4 ,valve ,stem ,too little4 ,too ,valve will not ,adjust gap 4#jji ,clearance4 much4 shut4 ,valve opens inlet1 4#jaj late1 closes exhaust4 early4 ,valve ,spring ,broken4 ,releases spring4 ,replace4 ,collar ,key4 ,cam4 ,worn cam contour4 ,valve lift re- ,previously given4 ,loose on shaft4 duced4 ,does not ,out of time4 lift valve4 ,valves operate at wrong time4 ,cam-shaft ,bearing4,looseness or wear4,valve timing ,replace4 altered4 ,valve lift decreased4 ,cam-shaft4 ,twisted4 ,valves out of ,previously given4 time4 ,cam ,fastening4 ,worn or broken4 ,valve action ,replace with new4 irregular4 ,valve ,operating ,loose in guide4 ,alters valve ,replace with new4 ,plunger4 timing4 ,valve ,plunger ,wear in bore4 ,alters valve ,replace or bush4 ,guide4 ,loose on engine timing4 ,fasten securely4 base4 ,timing ,gears4 ,not properly ,valves out of ,retime properly4 meshed4 ,loose on time4 ,valves do ,fasten to shaft4 shaft4 not operate4 ,piston4 ,walls scored4 ,leakage of gas4 ,smooth up if possible4 ,piston ,head4 ,carbon deposits4 ,cause premature ,previously given4 ,crack or blowhole ignition4 7rare74 ,piston ,rings4 ,no spring4 ,loose ,leakage weakens ,previously given4 in grooves4 ,worn suction4 or broken4 ,cylinder ,wall4 ,scored by wrist- ,gas leaks by4 ,poor,previously given4 pin4 ,scored by suction4 lack of oil4 ---------------------------------------- ---------------------------------- ,,ignition ,,system ,,troubles ,,only ,motor ,will ,not ,start or ,starts ,hard ,loose ,battery ,terminal4 ,magneto ,ground ,wire ,shorted4 ,magneto ,defective 7,no ,spark at ,plugs74 ,broken ,spark ,plug ,insulation4 ,carbon ,deposits or ,oil ,between ,plug ,points4 ,spark-,plug ,points ,too ,near ,together or ,far ,apart4 ,wrong ,cables to ,plugs4 ,short ,circuited ,secondary ,cable4 ,broken ,secondary ,cable4 ,dry ,battery ,weak4 ,storage ,battery ,discharged4 ,battery ,systems ,poor ,contact at ,timer4 ,only4 ,timer ,points ,dirty4 ,poor ,contact at ,switch4 ,primary ,wires ,broken1 or ,short ,circuited4 ,battery and ,battery ,grounded in ,metal ,container4 ,coil ,ignition ,battery ,connectors ,broken or ,loose4 ,system ,only4 ,timer ,points ,out of ,adjustment4 ,defects in ,induction ,coil4 ,ignition ,timing ,wrong1 ,spark ,too ,late or ,too ,early4 ,defective ,platinum ,points in ,breaker ,box 7,magneto74 ,points ,not ,separating4 ,broken ,contact ,maker ,spring4 ,no ,contact at ,secondary ,collector ,brush4 ,platinum ,contact ,points ,burnt or ,pitted4 ,contact ,breaker ,bell ,crank ,stuck4 ,fiber ,bushing in ,bell ,crank ,swollen4 ,short ,circuiting ,spring ,always in ,contact4 ,dirt or ,water in ,magneto ,casing4 ,oil in ,contact ,breaker4 ,oil ,soaked ,brush and ,collector ,ring4 ,distributor ,filled with ,carbon ,particles4 ,motor ,stops ,without ,warning ,broken ,magneto ,carbon ,brush4 ,broken ,lead ,wire4 ,broken ,ground ,wire4 ,battery ,ignition ,systems4 ,water on ,high ,tension ,magneto ,terminal4 ,main ,secondary ,cable ,burnt ,through by ,hot ,exhaust ,pipe 7,transformer ,coil1 ,magneto ,systems74 ,particle of ,carbon ,between ,spark ,plug ,points4 ,magneto ,short ,circuited by ,ground ,wire4 ,magneto ,out of ,time1 ,due to ,slipping ,drive4 ,water or ,oil in ,safety ,spark ,gap 7,multi-cylinder ,magneto74 ,magneto ,contact ,breaker or ,timer ,stuck in ,retard ,position4 ,worn ,fiber ,block in ,magneto ,contact ,breaker4 ,binding ,fiber ,bushing in ,contact ,breaker ,bell ,crank4 ,spark ,advance ,rod or ,wire ,broken4 ,contact ,breaker ,parts ,stuck4 ,motor ,runs ,irregularly or ,misfires ,loose ,wiring or ,terminals4 ,broken ,spark-,plug ,insulator4 ,spark-,plug ,points ,sooted or ,oily4 ,wrong ,spark ,gap at ,plug ,points4 ,leaking ,secondary ,cable4 ,prematurely ,grounded ,primary ,wire4 ,batteries ,running ,down 7,battery ,ignition only74 ,poor ,adjustment of ,contact ,points at ,timer4 ,wire ,broken ,inside of ,insulation4 ,loose ,platinum ,points in ,magneto4 ,weak ,contact ,spring4 ,broken ,collector ,brush4 ,dirt in ,magneto ,distributor ,casing or ,contact ,breaker4 ,worn ,fiber ,block or ,cam ,plate in ,magneto4 ,worn ,cam or ,contact ,roll in ,timer 7,battery ,system only74 ,dirty ,oil in ,timer4 ,sticking ,coil ,vibrators4 ,coil ,vibrator ,points ,pitted4 ,oil ,soaked ,magneto ,winding4 ,punctured ,magneto or ,coil ,winding4 ,distributor ,contact ,segments ,rough4 ,sulphated ,storage ,battery ,terminals4 ,weak ,magnets in ,magneto4 ,poor ,contact at ,magneto ,contact ,breaker ,points4 ,,defects ,,in ,,electrical ,,system ,,components ,to further simplify the location of electrical system faults it is thought desirable to outline the defects that can be present in the various parts of the individual devices comprising the ignition system4 ,if an airplane engine is provided with magneto ignition solely1 as most engines are at the present time1 no attention need be paid to such items as storage or dry batteries1 timer or induction coil4 ,there seems to be some development in the direction of battery ignition so it has been considered desirable to include components of these systems as well as the almost universally used magneto group4 ,spark-plugs1 wiring and switches are needed with either system4 ,,spark-,,plugs ,,defect ,,trouble ,,caused ,,remedy ,insulation cracked4 ,plug inoperative4 ,new insulation4 ,insulation oil soaked4 ,cylinder misfires4 ,clean4 ,carbon deposits4 ,short circuited spark4 ,remove4 ,insulator loose4 ,cylinder misfires4 ,tighten4 ,gasket broken4 ,gas leaks by4 ,new gasket4 ,electrode loose on shell4 ,cylinder misfires4 ,tighten4 ,wire loose in insulator4 ,cylinder misfires4 ,tighten4 ,air gap too close4 ,short circuits spark4 ,set correctly4 ,air gap too wide4 ,spark will not jump4 ,set points #a_/cb apart4 ,loose terminal4 ,cylinder may misfire4 ,tighten4 ,plug loose in cylinder4 ,gas leaks4 ,tighten4 ,mica insulation oil soaked4 ,short circuits spark4 ,replace4 ,,magneto ,,defect ,,trouble ,,caused ,,remedy ,dirty oil in distributor4 ,engine misfires4 ,clean4 ,metal dust in distributor4 ,engine misfires4 ,clean4 ,brushes not making contact4 ,current cannot pass4 ,strengthen spring4 ,distributor segments worn4 ,engine misfires4 ,secure even bearing4 ,collecting brush broken4 ,engine misfires4 ,new brush4 ,distributing brush broken4 ,engine misfires4 ,new brush4 ,oil soaked winding4 ,engine misfires4 ,clean4 ,magnets loose on pole ,engine misfires4 ,tighten screws4 pieces4 ,armature rubs4 ,engine misfires4 ,repair bearings4 ,bearings worn4 ,noisy4 ,replace4 ,magnets weak4 ,weak spark4 ,recharge4 ,contact breaker points ,engine misfires4 ,clean4 pitted4 ,breaker points out of ,engine misfires4 ,reset4 adjustment4 ,defective winding 7rare74 ,no spark4 ,replace4 ,punctured condenser 7rare74 ,weak or no spark4 ,replace4 ,driving gear loose4 ,noise4 ,tighten4 ,magneto armature out of ,spark will not fire ,retime4 time4 charge4 ,magneto loose on base4 ,misfiring and noisy4 ,tighten4 ,contact breaker cam worn4 ,misfiring4 ,replace4 ,fibre shoe or rolls worn ,misfiring4 ,replace4 7,bosch74 ,fibre bushing binding in ,misfiring4 ,ream slightly4 contact lever 7,bosch74 ,contact lever return spring ,no spark4 ,replace4 broken4 ,contact lever return spring ,misfiring4 ,replace4 weak4 ,ground wire grounded4 ,no spark4 ,insulate4 ,ground wire broken4 ,engine will not stop4 ,connect up4 ,safety spark gap dirty4 ,no spark4 ,clean4 ,fused metal in spark gap4 ,no spark4 ,remove4 ,safety spark gap points too ,misfiring4 ,set properly4 close4 ,loose distributor terminals4 ,misfiring4 ,tighten4 ,contact breaker sticks4 ,no spark control4 ,remove and clean bearings4 ,magneto switch short- ,no spark4 ,insulate4 circuited4 ,magneto switch open circuit4 ,no engine stop4 ,restore contact4 ,,storage ,,battery ,,defect ,,trouble ,,caused ,,remedy ,electrolyte low4 ,weak current4 ,replenish with distilled water4 ,loose terminals4 ,misfiring4 ,tighten4 ,sulphated terminals4 ,misfiring4 ,clean thoroughly and coat with vaseline4 ,battery discharged4 ,misfiring or no spark4 ,new charge4 ,electrolyte weak4 ,weak current4 ,bring to proper specific gravity4 ,plates sulphated4 ,poor capacity4 ,special slow charge4 ,sediment or mud in bottom4 ,weak current4 ,clean out4 ,active material loose in ,poor capacity4 ,new plates4 grids4 ,moisture or acid on top of ,shorts terminals4 ,remove4 cells4 ,plugged vent cap4 ,buckles cell jars4 ,make vent hole4 ,cracked vent cap4 ,acid spills out4 ,new cap4 ,cracked cell jar4 ,electrolyte runs out4 ,new jar4 ,,dry ,,cell ,,battery ,,defect ,,trouble ,,caused ,,remedy ,broken wires4 ,no current4 ,new wires4 ,loose terminals4 ,misfiring4 ,tighten4 ,weak cell 7#g amperes or ,misfiring4 ,new cells4 less74 ,cells in contact4 ,short circuit4 ,separate and insulate4 ,water in battery box4 ,short circuit4 ,dry out4 ,,timer ,,defect ,,trouble ,,caused ,,remedy ,contact segments worn or ,misfiring4 ,grind down pitted4 smooth4 ,platinum points pitted4 ,misfiring4 ,smooth with oil stone4 ,dirty oil or metal dust in ,misfiring4 ,clean out4 interior4 ,worn bearing4 ,misfiring4 ,replace4 ,loose terminals4 ,misfiring4 ,tighten4 ,worn revolving contact ,misfiring4 ,replace4 brush4 ,out of time4 ,irregular spark4 ,reset4 ,,induction ,,coil ,,defect ,,trouble ,,caused ,,remedy ,loose terminals4 ,misfiring4 ,tighten4 ,broken connections4 ,no spark4 ,make new joints4 ,vibrators out of adjustment4 ,misfiring4 ,readjust4 ,vibrator points pitted4 ,misfiring4 ,clean4 ,defective condenser rare4 ,no spark4 ,send to maker ,defective winding for repairs4 ,poor contact at switch4 ,misfiring4 ,tighten4 ,broken internal wiring4 ,no spark4 ,replace4 ,poor coil unit4 ,one cylinder affected4 ,replace4 ,,wiring ,,defect ,,trouble ,,caused ,,remedy ,loose terminals anywhere4 ,misfiring4 ,tighten4 ,broken plug wire4 ,one cylinder will not ,replace4 fire4 ,broken timer wire4 ,one coil will not buzz4 ,replace4 ,broken main battery wire4 ,no spark4 ,replace4 ,broken battery ground wire4 ,broken magneto ground wire4 ,engine will not stop4 ,replace4 ,chafed insulation anywhere4 ,misfiring4 ,insulate4 ,short circuit anywhere4 ,,carburetion ,,system ,,faults ,,summarized ,motor ,starts ,hard or ,will ,not ,start ,no ,gasoline in ,tank4 ,no ,gasoline in ,carburetor ,float ,chamber4 ,tank ,shut-,off ,closed4 ,clogged ,filter ,screen4 ,fuel ,supply ,pipe ,clogged4 ,gasoline ,level ,too ,low4 ,gasoline ,level ,too ,high 7,flooding74 ,bent or ,stuck ,float ,lever4 ,loose or ,defective ,inlet ,manifold4 ,not ,enough ,gasoline at ,jet4 ,cylinders ,flooded with ,gas4 ,fuel ,soaked ,cork ,float 7,causes ,flooding74 ,water in ,carburetor ,spray ,nozzle4 ,dirt in ,float ,chamber4 ,gas ,mixture ,too ,lean4 ,carburetor ,frozen 7,winter ,only74 ,motor ,stops ,in ,flight ,gasoline ,shut-,off ,valve ,jarred ,closed4 ,gasoline ,supply ,pipe ,clogged4 ,no ,gasoline in ,tank4 ,spray ,nozzle ,stopped ,up4 ,water in ,spray ,nozzle4 ,particles of ,carbon ,between ,spark-,plug ,points4 ,magneto ,short ,circuited by ,ground in ,wire4 ,air ,lock in ,gasoline ,pipe4 ,broken ,air ,line or ,leaky ,tank 7,pressure ,feed ,system ,only74 ,fuel ,supply ,pipe ,partially ,clogged4 ,air ,vent in ,tank ,filler ,cap ,stopped ,up 7,gravity and ,vacuum ,feed ,system74 ,float ,needle ,valve ,stuck4 ,water or ,dirt in ,spray ,nozzle4 ,mixture ,adjusting ,needle ,jarred ,loose 7,rotary ,motors ,only74 ,motor ,races1 ,will ,not ,throttle ,down ,air ,leak in ,inlet ,piping4 ,air ,leak ,through ,inlet ,valve ,guides4 ,control ,rods ,broken4 ,defective ,induction ,pipe ,joints4 ,leaky ,carburetor ,flange ,packing4 ,throttle ,not ,closing4 ,poor ,slow ,speed ,adjustment 7,zenith ,carburetor74 ,motor ,misfires ,carburetor ,float ,chamber ,getting ,dry4 ,water or ,dirt in ,gasoline4 ,poor ,gasoline ,adjustment 7,rotary ,motors74 ,not ,enough ,gasoline in ,float ,chamber4 ,too ,much ,gasoline1 ,carburetor ,flooding4 ,incorrect ,jet or ,choke 7,zenith ,carburetor74 ,broken ,cylinder ,head ,packing ,between ,cylinders4 ,noisy ,operation ,popping or ,blowing ,back in ,carburetor4 ,incorrectly ,timed ,inlet ,valves4 ,inlet ,valve ,not ,seating4 ,defective ,inlet ,valve ,spring4 ,dirt ,under ,inlet ,valve ,seat4 ,not ,enough ,gasoline 7,open ,needle ,valve74 ,muffler or ,manifold ,explosions4 ,mixture ,not ,exploding ,regularly4 ,exhaust ,valve ,sticking4 ,dirt ,under ,exhaust ,valve ,seat4 ,,chapter ,,xi ,tools for ,adjusting and ,erecting--,forms of ,wrenches--,use and ,care of ,files--,split ,pin ,removal and ,installation--,complete ,chisel ,set--,drilling ,machines--,drills1 ,reamers1 ,taps and ,dies-- ,measuring ,tools--,micrometer ,calipers and ,their ,use--,typical ,tool ,outfits--,special ,hall-,scott ,tools--,overhauling ,airplane ,engines --,taking ,engine ,down--,defects in ,cylinders--,carbon ,deposits1 ,cause and ,prevention--,use of ,carbon ,scrapers--,burning ,out ,carbon with ,oxygen--,repairing ,scored ,cylinders--,valve ,removal and ,inspection--,reseating and ,truing ,valves--,valve ,grinding ,processes--,depreciation in ,valve ,operating ,system--,piston ,troubles--,piston ,ring ,manipulation--,fitting ,piston ,rings-- ,wrist-,pin ,wear--,inspection and ,refitting of ,engine ,bearings-- ,scraping ,brasses to ,fit--,fitting ,connecting ,rods--,testing for ,bearing ,parallelism--,cam-,shafts and ,timing ,gears--,precautions in ,reassembling ,parts4 ,,tools ,,for ,,adjusting ,,and ,,erecting ,illustration3 ,fig4 #afc4--,practical ,hand ,tools ,useful in ,dismantling and ,repairing ,airplane ,engines4 ,a very complete outfit of small tools1 some of which are furnished as part of the tool equipment of various engines are shown in group at ,fig4 #afc4 ,this group includes all of the tools necessary to complete a very practical kit and it is not unusual for the mechanic who is continually dismantling and erecting engines to possess even a larger assortment than indicated4 ,the small bench vise provided is a useful auxiliary that can be clamped to any convenient bench or table or even fuselage longeron in an emergency and should have jaws at least three inches wide and capable of opening four or five inches4 ,it is especially useful in that it will save trips to the bench vises1 as it has adequate capacity to handle practically any of the small parts that need to be worked on when making repairs4 ,a blow torch1 tinner's snips and soldering copper are very useful in sheet metal work and in making any repairs requiring the use of solder4 ,the torch can be used in any operation requiring a source of heat4 ,the large box wrench shown under the vise is used for removing large special nuts and sometimes has one end of the proper size to fit the valve chamber cap4 ,the piston ring removers are easily made from thin strips of sheet metal securely brazed or soldered to a light wire handle4 ,these are used in sets of three for removing and applying piston rings in a manner to be indicated4 ,the uses of the wrenches1 screw drivers1 and pliers shown are known to all and the variety outlined should be sufficient for all ordinary work of restoration4 ,the wrench equipment is very complete1 including a set of open end ,s-wrenches to fit all standard bolts1 a spanner wrench1 socket or box wrenches for bolts that are inaccessible with the ordinary type1 adjustable end wrenches1 a thin monkey wrench of medium size1 a bicycle wrench for handling small nuts and bolts1 a ,stillson wrench for pipe and a large adjustable monkey wrench for the stubborn fastenings of large size4 ,four different types of pliers are shown1 one being a parallel jaw type with size cutting attachment1 while the other illustrated near it is a combination parallel jaw type adapted for use on round work as well as in handling flat stock4 ,the most popular form of pliers is the combination pattern shown beneath the socket wrench set4 ,this is made of substantial drop forgings having a hinged joint that can be set so that a very wide opening at the jaws is possible4 ,these can be used on round work and for wire cutting as well as for handling flat work4 ,round nose pliers are very useful also4 ,a very complete set of files1 including square1 half round1 mill1 flat bastard1 three-cornered and rat tail are also necessary4 ,a hacksaw frame and a number of saws1 some with fine teeth for tubing and others with coarser teeth for bar or solid stock will be found almost indispensable4 ,a complete punch and chisel set should be provided1 samples of which are shown in the group while the complete outfit is outlined in another illustration4 ,a number of different forms and sizes of chisels are necessary1 as one type is not suitable for all classes of work4 ,the adjustable end wrenches can be used in many places where a monkey wrench cannot be fitted and where it will be difficult to use a wrench having a fixed opening4 ,the ,stillson pipe wrench is useful in turning studs1 round rods1 and pipes that cannot be turned by any other means4 ,a complete shop kit must necessarily include various sizes for ,stillson and monkey wrenches1 as no one size can be expected to handle the wide range of work the engine repairman must cope with4 ,three sizes of each form of wrench can be used1 one1 a #f inch1 is as small as is needed while1 a #ab inch tool will handle almost any piece of pipe or nut used in engine construction4 ,three or four sizes of hammers should be provided1 according to individual requirement1 these being small riveting1 medium and heavyweight machinist's hammers4 ,a very practical tool of this nature for the repair shop can be used as a hammer1 screw driver or pry iron4 ,it is known as the ,spartan hammer and is a tool steel drop forging in one piece having the working surfaces properly hardened and tempered while the metal is distributed so as to give a good balance to the head and a comfortable grip to the handle4 ,the hammer head provides a positive and comfortable ,t-handle when the tool is used as a screw driver or tommy bar4 ,machinist's hammers are provided with three types of heads1 these being of various weights4 ,the form most commonly used is termed the ball pein on account of the shape of the portion used for riveting4 ,the straight pein is just the same as the cross pein1 except that in the latter the straight portion is at right angles to the hammer handle1 while in the former it is parallel to that member4 ,,forms ,,of ,,wrenches ,wrenches have been made in infinite variety and there are a score or more patterns of different types of adjustable socket and off-set wrenches4 ,the various wrench types that differ from the more conventional monkey wrenches or those of the ,stillson pattern are shown at ,fig4 #afd4 ,the perfect handle is a drop forged open end form provided with a wooden handle similar to that used on a monkey wrench in order to provide a better grip for the hand4 ,the ,saxon wrench is a double alligator form1 so called because the jaws are in the form of a ,v-groove having one side of the ,v plain1 while the other is serrated in order to secure a tight grip on round objects4 ,in the form shown1 two jaws of varying sizes are provided1 one for large work1 the other to handle the smaller rods4 ,one of the novel features in connection with this wrench is the provision of a triple die block in the centre of the handle which is provided with three most commonly used of the standard threads including #e_/af-;inch-#ah1 #c_/h-;inch-#af1 and #a_/b-;inch-#ac4 ,this is useful in cleaning up burred threads on bolts before they are replaced1 as burring is unavoidable if it has been necessary to drive them out with a hammer4 ,the ,lakeside wrench has an adjustable pawl engaging with one of a series of notches by which the opening may be held in any desired position4 ,illustration3 ,fig4 #afd4--,wrenches are ,offered in ,many ,forms4 ,ever since the socket wrench was invented it has been a popular form because it can be used in many places where the ordinary open end or monkey wrench cannot be applied owing to lack of room for the head of the wrench4 ,a typical set which has been made to fit in a very small space is shown at ,d4 ,it consists of a handle1 which is nickel-plated and highly polished1 a long extension bar1 a universal joint and a number of case hardened cold drawn steel sockets to fit all commonly used standard nuts and bolt heads4 ,two screw-driver bits1 one small and the other large to fit the handle1 and a long socket to fit spark-plugs are also included in this outfit4 ,the universal joint permits one to remove nuts in a position that would be inaccessible to any other form of wrench1 as it enables the socket to be turned even if the handle is at one side of an intervening obstruction4 ,the ,pick-up wrench1 shown at ,e1 is used for spark-plugs and the upper end of the socket is provided with a series of grooves into which a suitable blade carried by the handle can be dropped4 ,the handle is pivoted to the top of the socket in such a way that the blades may be picked up out of the grooves by lifting on the end of the handle and dropped in again when the handle is swung around to the proper point to get another hold on the socket4 ,the ,miller wrench shown at ,f1 is a combination socket and open end type1 made especially for use with spark-plugs4 ,both the open end and the socket are convenient4 ,the ,handy set shown at ,g1 consists of a number of thin stamped wrenches of steel held together in a group by a simple clamp fitting1 which enables either end of any one of the four double wrenches to be brought into play according to the size of the nut to be turned4 ,the ,cronk wrench shown at ,h1 is a simple stamping having an alligator opening at one end and a stepped opening capable of handling four different sizes of standard nuts or bolt heads at the other4 ,such wrenches are very cheap and are worth many times their small cost1 especially for fitting nuts where there is not sufficient room to admit the more conventional pattern4 ,the ,starrett wrench set1 which is shown at ,i1 consists of a ratchet handle together with an extension bar and universal joint1 a spark-plug socket1 a drilling attachment which takes standard square shank drills from #a_/h-;inch to #a_/b-;inch in diameter1 a double ended screw-driver bit and several adjustments to go with the drilling attachment4 ,twenty-eight assorted cold drawn steel sockets similar in design to those shown at ,d1 to fit all standard sizes of square and hexagonal headed nuts are also included4 ,the reversible ratchet handle1 which may be slipped over the extension bar or the universal joint and which is also adapted to take the squared end of any one of the sockets is exceptionally useful in permitting1 as it does1 the instant release of pressure when it is desired to swing the handle back to get another hold on the nut4 ,the socket wrench sets are usually supplied in hard wood cases or in leather bags so that they may be kept together and protected against loss or damage4 ,with a properly selected socket wrench set1 either of the ratchet handle or ,t-handle form1 any nut on the engine may be reached and end wrenches will not be necessary4 ,,use ,,and ,,care ,,of ,,files ,mention has been previously made of the importance of providing a complete set of files and suitable handles4 ,these should be in various grades or degrees of fineness and three of each kind should be provided4 ,in the flat and half round files three grades are necessary1 one with coarse teeth for roughing1 and others with medium and fine teeth for the finishing cuts4 ,the round or rat tail file is necessary in filing out small holes1 the half round for finishing the interior of large ones4 ,half round files are also well adapted for finishing surfaces of peculiar contour1 such as the inside of bearing boxes1 connecting rod and main bearing caps1 etc4 ,square files are useful in finishing keyways or cleaning out burred splines1 while the triangular section or three-cornered file is of value in cleaning out burred threads and sharp corners4 ,flat files are used on all plane surfaces4 ,illustration3 ,fig4 #afe4--;,illustrating ,use and ,care of ,files4 ,the file brush shown at ,fig4 #afe1 ,a1 consists of a large number of wire bristles attached to a substantial wood back having a handle of convenient form so that the bristles may be drawn through the interstices between the teeth of the file to remove dirt and grease4 ,if the teeth are filled with pieces of soft metal1 such as solder or babbitt1 it may be necessary to remove this accumulation with a piece of sheet metal as indicated at ,fig4 #afe1 ,b4 ,the method of holding a file for working on plain surfaces when it is fitted with the regular form of wooden handle is shown at ,c1 while two types of handles enabling the mechanic to use the flat file on plain surfaces of such size that the handle type indicated at ,c1 could not be used on account of interfering with the surface finished are shown at ,d4 ,the method of using a file when surfaces are finished by draw filing is shown at ,e4 ,this differs from the usual method of filing and is only used when surfaces are to be polished and very little metal removed4 ,,split ,,pin ,,removal ,,and ,,insertion ,one of the most widely used of the locking means to prevent nuts or bolts from becoming loose is the simple split pin1 sometimes called a cotter pin4 ,these can be handled very easily if the special pliers shown at ,fig4 #aff1 ,a1 are used4 ,they have a curved jaw that permits of grasping the pin firmly and inserting it in the hole ready to receive it4 ,it is not easy to insert these split pins by other means because the ends are usually spread out and it is hard to enter the pin in the hole4 ,with the cotter pin pliers the ends may be brought close together and as the plier jaws are small the pin may be easily pushed in place4 ,another use of this plier1 also indicated1 is to bend over the ends of the split pin in order to prevent it from falling out4 ,to remove these pins a simple curved lever1 as shown at ,fig4 #aff1 ,b1 is used4 ,this has one end tapering to a point and is intended to be inserted in the eye of the cotter pin1 the purchase offered by the handle permitting of ready removal of the pin after the ends have been closed by the cotter pin pliers4 ,,complete ,,chisel ,,set ,illustration3 ,fig4 #aff4--,outlining ,use of ,cotter ,pin ,pliers1 ,spring ,winder1 and ,showing ,practical ,outfit of ,chisels4 ,a complete chisel set suitable for repair shop use is also shown at ,fig4 #aff4 ,the type at ,c is known as a cape chisel and has a narrow cutting point and is intended to chip keyways1 remove metal out of corners and for all other work where the broad cutting edge chisel1 shown at ,d1 cannot be used4 ,the form with the wide cutting edge is used in chipping1 cutting sheet metal1 etc4 ,at ,e1 a round nose chisel used in making oil ways is outlined1 while a similar tool having a pointed cutting edge and often used for the same purpose is shown at ,f4 ,the centre punch depicted at ,g1 is very useful for marking parts either for identification or for drilling4 ,in addition to the chisels shown1 a number of solid punches or drifts resembling very much that shown at ,e1 except that the point is blunt should be provided to drive out taper pins1 bolts1 rivets1 and other fastenings of this nature4 ,these should be provided in the common sizes4 ,a complete set of real value would start at #a_/h-;inch and increase by increments of #a_/cb-;inch up to #a_/b-;inch4 ,a simple spring winder is shown at ,fig4 #aff1 ,h1 this making it possible for the repairman to wind coil springs1 either on the lathe or in the vise4 ,it will handle a number of different sizes of wire and can be set to space the coils as desired4 ,,drilling ,,machines ,illustration3 ,fig4 #afg4--;,forms of ,hand ,operated ,drilling ,machines4 ,drilling machines may be of two kinds1 hand or power operated4 ,for drilling small holes in metal it is necessary to run the drill fast1 therefore the drill chuck is usually driven by gearing in order to produce high drill speed without turning the handle too fast4 ,a small hand drill is shown at ,fig4 #afg1 ,a4 ,as will be observed1 the chuck spindle is driven by a small bevel pinion1 which in turn1 is operated by a large bevel gear turned by a crank4 ,the gear ratio is such that one turn of the handle will turn the chuck five or six revolutions4 ,a drill of this design is not suited for drills any larger than one-quarter inch4 ,for use with drills ranging from one-eighth to three-eighths1 or even half-inch the hand drill presses shown at ,c and ,d are used4 ,these have a pad at the upper end by which pressure may be exerted with the chest in order to feed the drill into the work1 and for this reason they are termed breast drills4 ,the form at ,c has compound gearing1 the drill chuck being driven by the usual form of bevel pinion in mesh with a larger bevel gear at one end of a countershaft4 ,a small helical spur pinion at the other end of this countershaft receives its motion from a larger gear turned by the hand crank4 ,this arrangement of gearing permits of high spindle speed without the use of large gears1 as would be necessary if but two were used4 ,the form at ,d gives two speeds1 one for use with small drills is obtained by engaging the lower bevel pinion with the chuck spindle and driving it by the large ring gear4 ,the slow speed is obtained by shifting the clutch so that the top bevel pinion drives the drill chuck4 ,as this meshes with a gear but slightly larger in diameter1 a slow speed of the drill chuck is possible4 ,breast drills are provided with a handle screwed into the side of the frame1 these are used to steady the drill press4 ,for drilling extremely large holes which are beyond the capacity of the usual form of drill press the ratchet form shown at ,b1 may be used or the bit brace outlined at ,e4 ,the drills used with either of these have square shanks1 whereas those used in the drill presses have round shanks4 ,the bit brace is also used widely in wood work and the form shown is provided with a ratchet by which the bit chuck may be turned through only a portion of a revolution in either direction if desired4 ,,drills1 ,,reamers1 ,,taps ,,and ,,dies ,in addition to the larger machine tools and the simple hand tools previously described1 an essential item of equipment of any engine or plane repair shop1 even in cases where the ordinary machine tools are not provided1 is a complete outfit of drills1 reamers1 and threading tools4 ,drills are of two general classes1 the flat and the twist drills4 ,the flat drill has an angle between cutting edges of about #aaj degrees and is usually made from special steel commercially known as drill rod4 ,a flat drill cannot be fed into the work very fast because it removes metal by a scraping1 rather than a cutting process4 ,the twist drill in its simplest form is cylindrical throughout the entire length and has spiral flutes which are ground off at the end to form the cutting lip and which also serve to carry the metal chips out of the holes4 ,the simplest form of twist drill used is shown at ,fig4 #afh1 ,c1 and is known as a chuck drill1 because it must be placed in a suitable chuck to turn it4 ,a twist drill removes metal by cutting and it is not necessary to use a heavy feed as the drill will tend to feed itself into the work4 ,illustration3 ,fig4 #afh4--;,forms of ,drills ,used in ,hand and ,power ,drilling ,machines4 ,larger drills than #c_/d-;inch are usually made with a tapered shank as shown at ,fig4 #afh1 ,b4 ,at the end of the taper a tongue is formed which engages with a suitable opening in the collet1 as the piece used to support the drill is called4 ,the object of this tongue is to relieve the tapered portion of the drill from the stress of driving by frictional contact alone1 as this would not turn the drill positively and the resulting slippage would wear the socket1 this depreciation changing the taper and making it unfit for other drills4 ,the tongue is usually proportioned so it is adequate to drive the drill under any condition4 ,a small keyway is provided in the collet into which a tapering key of flat stock may be driven against the end of the tongue to drive the drill from the spindle4 ,a standard taper for drill shanks generally accepted by the machine trade is known as the ,morse and is a taper of five-eighths of an inch to the foot4 ,the ,brown and ,sharp form tapers six-tenths of an inch to the foot4 ,care must be taken1 therefore1 when purchasing drills and collets1 to make sure that the tapers coincide1 as no attempt should be made to run a ,morse taper in a ,brown and ,sharp collet1 or vice versa4 ,sometimes cylindrical drills have straight flutes1 as outlined at ,fig4 #afh1 ,a4 ,such drills are used with soft metals and are of value when the drill is to pass entirely through the work4 ,the trouble with a drill with spiral flutes is that it will tend to draw itself through as the cutting lips break through4 ,this catching of the drill may break it or move the work from its position4 ,with a straight flute drill the cutting action is practically the same as with the flat drill shown at ,fig4 #afh1 ,e and ,f4 ,if a drill is employed in boring holes through close-grained1 tough metals1 as wrought or malleable iron and steel1 the operation will be facilitated by lubricating the drill with plenty of lard oil or a solution of soda and water4 ,either of these materials will effectually remove the heat caused by the friction of the metal removed against the lips of the drill1 and the danger of heating the drill to a temperature that will soften it by drawing the temper is minimized4 ,in drilling large or deep holes it is good practice to apply the lubricating medium directly at the drill point4 ,special drills of the form shown at ,fig4 #afh1 ,b1 having a spiral oil tube running in a suitably formed channel1 provides communication between the point of the drill and a suitable receiving hole on a drilled shank4 ,the oil is supplied by a pump and its pressure not only promotes positive circulation and removal of heat1 but also assists in keeping the hole free of chips4 ,in drilling steel or wrought iron1 lard oil applied to the point of the drill will facilitate the drilling1 but this material should never be used with either brass or cast iron4 ,the sizes to be provided depend upon the nature of the work and the amount of money that can be invested in drills4 ,it is common practice to provide a set of drills1 such as shown at ,fig4 #afi1 which are carried in a suitable metal stand1 these being known as number drills on account of conforming to the wire gauge standards4 ,number drills do not usually run higher than #e_/af inch in diameter4 ,beyond this point drills are usually sold by the diameter4 ,a set of chuck drills1 ranging from #c_/h to #c_/d inch1 advancing by #a_/cb inch1 and a set of ,morse taper shank drills ranging from #c_/d to #a-a_/d inches1 by increments of #a_/af inch1 will be all that is needed for the most pretentious repair shop1 as it is cheaper to bore holes larger than #a-a_/d inches with a boring tool than it is to carry a number of large drills in stock that would be used very seldom1 perhaps not enough to justify their cost4 ,illustration3 ,fig4 #afi4--,useful ,set of ,number ,drills1 ,showing ,stand for ,keeping ,these in an ,orderly ,manner4 ,in grinding drills1 care must be taken to have the lips of the same length1 so that they will form the same angle with the axis4 ,if one lip is longer than the other1 as shown in the flat drill at ,fig4 #afh1 ,e1 the hole will be larger than the drill size1 and all the work of cutting will come upon the longest lip4 ,the drill ends should be symmetrical1 as shown at ,fig4 #afh1 ,f4 ,illustration3 ,fig4 #agj4--;,illustrating ,standard ,forms of ,hand and ,machine ,reamers4 ,it is considered very difficult to drill a hole to an exact diameter1 but for the most work a variation of a few thousandths of an inch is of no great moment4 ,where accuracy is necessary1 holes must be reamed out to the required size4 ,in reaming1 a hole is drilled about #a_/cb inch smaller than is required1 and is enlarged with a cutting tool known as the reamer4 ,reamers are usually of the fluted form shown at ,fig4 #agj1 ,a4 ,tools of this nature are not designed to remove considerable amounts of metal1 but are intended to augment the diameter of the drill hole by only a small fraction of an inch4 ,reamers are tapered slightly at the point in order that they will enter the hole easily1 but the greater portion of the fluted part is straight1 all cutting edges being parallel4 ,hand reamers are made in either the straight or taper forms1 that at ,a1 ,fig4 #agj1 being straight1 while ,b has tapering flutes4 ,they are intended to be turned by a wrench similar to that employed in turning a tap1 as shown at ,fig4 #agb1 ,c4 ,the reamer shown at ,fig4 #agj1 ,c1 is a hand reamer4 ,the form at ,d has spiral flutes similar to a twist drill1 and as it is provided with a taper shank it is intended to be turned by power through the medium of a suitable collet4 ,as the solid reamers must become reduced in size when sharpened1 various forms of inserted blade reamers have been designed4 ,one of these is shown at ,e1 and as the cutting surfaces become reduced in diameter it is possible to replace the worn blades with others of proper size4 ,expanding reamers are of the form shown at ,f4 ,these have a bolt passing through that fits into a tapering hole in the interior of the split reamer portion of the tool4 ,if the hole is to be enlarged a few thousandths of an inch1 it is possible to draw up on the nut just above the squared end of the shank1 and by drawing the tapering wedge farther into the reamer body1 the cutting portion will be expanded and will cut a larger hole4 ,reamers must be very carefully sharpened or there will be a tendency toward chattering with a consequent production of a rough surface4 ,there are several methods of preventing this chattering1 one being to separate the cutting edges by irregular spaces1 while the most common method1 and that to be preferred on machine reamers1 is to use spiral flutes1 as shown at ,fig4 #agj1 ,d4 ,special taper reamers are made to conform to the various taper pin sizes which are sometimes used in holding parts together in an engine4 ,a taper of #a_/af inch per foot is intended for holes where a pin1 once driven in1 is to remain in place4 ,when it is desired that the pin be driven out1 the taper is made steeper1 generally #a_/d inch per foot1 which is the standard taper used on taper pins4 ,illustration3 ,fig4 #aga4--,tools for ,thread ,cutting4 ,when threads are to be cut in a small hole1 it will be apparent that it will be difficult to perform this operation economically on a lathe1 therefore when internal threading is called for1 a simple device known as a tap is used4 ,there are many styles of taps1 all conforming to different standards4 ,some are for metric or foreign threads1 some conform to the ,american standards1 while others are used for pipe and tubing4 ,hand taps are the form most used in repair shops1 these being outlined at ,fig4 #aga1 ,a and ,b4 ,they are usually sold in sets of three1 known respectively as taper1 plug1 and bottoming4 ,the taper tap is the one first put into the hole1 and is then followed by the plug tap which cuts the threads deeper4 ,if it is imperative that the thread should be full size clear to the bottom of the hole1 the third tap of the set1 which is straight-sided1 is used4 ,it would be difficult to start a bottoming tap into a hole because it would be larger in diameter at its point than the hole4 ,the taper tap1 as shown at ,a1 ,fig4 #aga1 has a portion of the cutting lands ground away at the point in order that it will enter the hole4 ,the manipulation of a tap is not hard1 as it does not need to be forced into the work1 as the thread will draw it into the hole as the tap is turned4 ,the tapering of a tap is done so that no one thread is called upon to remove all of the metal1 as for about half way up the length of the tap each succeeding thread is cut a little larger by the cutting edge until the full thread enters the hole4 ,care must be taken to always enter a tap straight in order to have the thread at correct angles to the surface4 ,in cutting external threads on small rods or on small pieces1 such as bolts and studs1 it is not always economical to do this work in the lathe1 especially in repair work4 ,dies are used to cut threads on pieces that are to be placed in tapped holes that have been threaded by the corresponding size of tap4 ,dies for small work are often made solid1 as shown at ,fig4 #aga1 ,c1 but solid dies are usually limited to sizes below #a_/b inch4 ,sometimes the solid die is cylindrical in shape1 with a slot through one side which enables one to obtain a slight degree of adjustment by squeezing the slotted portion together4 ,large dies1 or the sizes over #a_/b inch1 are usually made in two pieces in order that the halves may be closed up or brought nearer together4 ,the advantage of this form of die is that either of the two pieces may be easily sharpened1 and as it may be adjusted very easily the thread may be cut by easy stages4 ,for example1 the die may be adjusted to cut large1 which will produce a shallow thread that will act as an accurate guide when the die is closed up and a deeper thread cut4 ,illustration3 ,fig4 #agb4--,showing ,holder ,designs for ,one- and ,two-,piece ,thread ,cutting ,dies4 ,a common form of die holder for an adjustable die is shown at ,fig4 #agb1 ,a4 ,as will be apparent1 it consists of a central body portion having guide members to keep the die pieces from falling out and levers at each end in order to permit the operator to exert sufficient force to remove the metal4 ,the method of adjusting the depth of thread with a clamp screw when a two-piece die is employed is also clearly outlined4 ,the diestock shown at ,b is used for the smaller dies of the one-piece pattern1 having a slot in order that they may be closed up slightly by the clamp screw4 ,the reverse side of the diestock shown at ,b is outlined below it1 and the guide pieces1 which may be easily moved in or out1 according to the size of the piece to be threaded by means of eccentrically disposed semi-circular slots in the adjustment plate1 are shown4 ,these movable guide members have small pins let into their surface which engage the slots1 and they may be moved in or out1 as desired1 according to the position of the adjusting plate4 ,the use of the guide pieces makes for accurate positioning or centering of the rod to be threaded4 ,dies are usually sold in sets1 and are commonly furnished as a portion of a complete outfit such as outlined at ,fig4 #agc4 ,that shown has two sizes of diestock1 a tap wrench1 eight assorted dies1 eight assorted taps1 and a small screw driver for adjusting the die4 ,an automobile repair shop should be provided with three different sets of taps and dies1 as three different standards for the bolts and nuts are used in fastening automobile components4 ,these are the ,american1 metric 7used on foreign engines71 and the ,s4 ,a4 ,e4 standard threads4 ,a set of pipe dies and taps will also be found useful4 ,illustration3 ,fig4 #agc4--,useful ,outfit of ,taps and ,dies for the ,engine ,repair ,shop4 ,,measuring ,,tools ,the tool outfit of the machinist or the mechanic who aspires to do machine work must include a number of measuring tools which are not needed by the floor man or one who merely assembles and takes apart the finished pieces4 ,the machinist who must convert raw material into finished products requires a number of measuring tools1 some of which are used for taking only approximate measurements1 such as calipers and scales1 while others are intended to take very accurate measurements1 such as the ,vernier and the micrometer4 ,a number of common forms of calipers are shown at ,fig4 #agd4 ,these are known as inside or outside calipers1 depending upon the measurements they are intended to take4 ,that at ,a is an inside caliper1 consisting of two legs1 ,a and ,d1 and a gauging piece1 ,b1 which can be locked to leg ,a1 or released from that member by the screw1 ,c4 ,the object of this construction is to permit of measurements being taken at the bottom of a two diameter hole1 where the point to be measured is of larger diameter than the portion of the hole through which the calipers entered4 ,it will be apparent that the legs ,a and ,d must be brought close together to pass through the smaller holes4 ,this may be done without losing the setting1 as the guide bar ,b will remain in one position as determined by the size of the hole to be measured1 while the leg ,a may be swung in to clear the obstruction as the calipers are lifted out4 ,when it is desired to ascertain the measurements the leg ,a is pushed back into place into the slotted portion of the guide ,b1 and locked by the clamp screw ,c4 ,a tool of this form is known as an internal transfer caliper4 ,illustration3 ,fig4 #agd4--;,common ,forms of ,inside and ,outside ,calipers4 ,the form of caliper shown at ,b is an outside caliper4 ,those at ,c and ,d are special forms for inside and outside work1 the former being used1 if desired1 as a divider1 while the latter may be employed for measuring the walls of tubing4 ,the calipers at ,e are simple forms1 having a friction joint to distinguish them from the spring calipers shown at ,b1 ,c and ,d4 ,in order to permit of ready adjustment of a spring caliper1 a split nut as shown at ,g is sometimes used4 ,a solid nut caliper can only be adjusted by screwing the nut in or out on the screw1 which may be a tedious process if the caliper is to be set from one extreme to the other several times in succession4 ,with a slip nut as shown at ,g it is possible to slip it from one end of the thread to the other without turning it1 and of locking it in place at any desired point by simply allowing the caliper leg to come in contact with it4 ,the method of adjusting a spring caliper is shown at ,fig4 #agd1 ,h4 ,among the most common of the machinist's tools are those used for linear measurements4 ,the usual forms are shown in group1 ,fig4 #age4 ,the most common tool1 which is widely known1 is the carpenter's folding two-foot rule or the yardstick4 ,while these are very convenient for taking measurements where great accuracy is not required1 the machinist must work much more accurately than the carpenter1 and the standard steel scale which is shown at ,d1 is a popular tool for the machinist4 ,the steel scale is in reality a graduated straight edge and forms an important part of various measuring tools4 ,these are made of high grade steel and vary from #a to #dh inches in length4 ,they are carefully hardened in order to preserve the graduations1 and all surfaces and edges are accurately ground to insure absolute parallelism4 ,the graduations on the high grade scales are produced with a special device known as a dividing engine1 but on cheaper scales1 etching suffices to provide a fairly accurate graduation4 ,the steel scales may be very thin and flexible1 or may be about an eighth of an inch thick on the twelve-inch size1 which is that commonly used with combination squares1 protractors and other tools of that nature4 ,the repairman's scale should be graduated both with the ,english system1 in which the inches are divided into eighths1 sixteenths1 thirty-secondths and sixty-fourths1 and also in the metric system1 divided into millimeters and centimeters4 ,some machinists use scales graduated in tenths1 twentieths1 fiftieths and hundredths4 ,this is not as good a system of graduation as the more conventional one first described4 ,illustration3 ,fig4 #age4--,measuring ,appliances for the ,machinist and ,floor ,man4 ,some steel scales are provided with a slot or groove cut the entire length on one side and about the center of the scales4 ,this permits the attachment of various fittings such as the protractor head1 which enables the machinist to measure angles1 or in addition the heads convert the scale into a square or a tool permitting the accurate bisecting of pieces of circular section4 ,two scales are sometimes joined together to form a right angle1 such as shown at ,fig4 #age1 ,c4 ,this is known as a square and is very valuable in ascertaining the truth of vertical pieces that are supposed to form a right angle with a base piece4 ,the ,vernier is a device for reading finer divisions on a scale than those into which the scale is divided4 ,sixty-fourths of an inch are about the finest division that can be read accurately with the naked eye4 ,when fine work is necessary a ,vernier is employed4 ,this consists essentially of two rules so graduated that the true scale has each inch divided into ten equal parts1 the upper or ,vernier portion has ten divisions occupying the same space as nine of the divisions of the true scale4 ,it is evident1 therefore1 that one of the divisions of the ,vernier is equal to nine-tenths of one of those on the true scale4 ,if the ,vernier scale is moved to the right so that the graduations marked #a shall coincide1 it will have moved one-tenth of a division on the scale or one-hundredth of an inch4 ,when the graduations numbered #e coincide the ,vernier will have moved five-hundredths of an inch2 when the lines marked #j and #aj coincide1 the ,vernier will have moved nine-hundredths of an inch1 and when #aj on the ,vernier comes opposite #aj on the scales1 the upper rule will have moved ten-hundredths of an inch1 or the whole of one division on the scale4 ,by this means the scale1 though it may be graduated only to tenths of an inch1 may be accurately set at points with positions expressed in hundredths of an inch4 ,when graduated to read in thousandths1 the true scale is divided into fifty parts and the ,vernier into twenty parts4 ,each division of the ,vernier is therefore equal to nineteen-twentieths of one of the true scale4 ,if the ,vernier be moved so the lines of the first division coincide1 it will have moved one-twentieth of one-fiftieth1 or 4#jja inch4 ,the ,vernier principle can be readily grasped by studying the section of the ,vernier scale and true scale shown at ,fig4 #agf1 ,a4 ,illustration3 ,fig4 #agf4--;,at ,left1 ,special ,form of ,vernier ,caliper for ,measuring ,gear ,teeth2 at ,right1 ,micrometer for ,accurate ,internal ,measurements4 ,the caliper scale which is shown at ,fig4 #age1 ,a1 permits of taking the over-all dimension of any parts that will go between the jaws4 ,this scale can be adjusted very accurately by means of a fine thread screw attached to a movable jaw and the divisions may be divided by eye into two parts if one sixty-fourth is the smallest of the divisions4 ,a line is indicated on the movable jaw and coincides with the graduations on the scale4 ,as will be apparent1 if the line does not coincide exactly with one of the graduations it will be at some point between the lines and the true measurement may be approximated without trouble4 ,a group of various other measuring tools of value to the machinist is shown at ,fig4 #agg4 ,the small scale at ,a is termed a center gauge1 because it can be used to test the truth of the taper of either a male or female lathe center4 ,the two smaller nicks1 or v's1 indicate the shape of a standard thread1 and may be used as a guide for grinding the point of a thread-cutting tool4 ,the cross level which is shown at ,b is of marked utility in erecting1 as it will indicate absolutely if the piece it is used to test is level4 ,it will indicate if the piece is level along its width as well as its length4 ,illustration3 ,fig4 #agg4--,measuring ,appliances of ,value in ,airplane ,repair ,work4 ,a very simple attachment for use with a scale that enables the machinist to scribe lines along the length of a cylindrical piece is shown at ,fig4 #agg1 ,c4 ,these are merely small wedge-shaped clamps having an angular face to rest upon the bars4 ,the thread pitch gauge which is shown at ,fig4 #agg1 ,d1 is an excellent pocket tool for the mechanic1 as it is often necessary to determine without loss of time the pitch of the thread on a bolt or in a nut4 ,this consists of a number of leaves having serrations on one edge corresponding to the standard thread it is to be used in measuring4 ,the tool shown gives all pitches up to #dh threads per inch4 ,the leaves may be folded in out of the way when not in use1 and their shape admits of their being used in any position without the remainder of the set interfering with the one in use4 ,the fine pitch gauges have slim1 tapering leaves of the correct shape to be used in finding the pitch of small nuts4 ,as the tool is round when the leaves are folded back out of the way1 it is an excellent pocket tool1 as there are no sharp corners to wear out the pocket4 ,practical application of a ,vernier having measuring heads of special form for measuring gear teeth is shown at ,fig4 #agf1 ,a4 ,as the action of this tool has been previously explained1 it will not be necessary to describe it further4 ,,micrometer ,,calipers ,,and ,,their ,,use ,where great accuracy is necessary in taking measurements the micrometer caliper1 which in the simple form will measure easily 4#jja inch 7one-thousandth part of an inch7 and when fitted with a ,vernier that will measure 4#jjja inch 7one ten-thousandth part of an inch71 is used4 ,the micrometer may be of the caliper form for measuring outside diameters or it may be of the form shown at ,fig4 #agf1 ,b1 for measuring internal diameters4 ,the operation of both forms is identical except that the internal micrometer is placed inside of the bore to be measured while the external form is used just the same as a caliper4 ,the form outlined will measure from one and one-half to six and a half inches as extension points are provided to increase the range of the instrument4 ,the screw has a movement of one-half inch and a hardened anvil is placed in the end of the thimble in order to prevent undue wear at that point4 ,the extension points or rods are accurately made in standard lengths and are screwed into the body of the instrument instead of being pushed in1 this insuring firmness and accuracy4 ,two forms of micrometers for external measurements are shown at ,fig4 #agh4 ,the top one is graduated to read in thousandths of an inch1 while the lower one is graduated to indicate hundredths of a millimeter4 ,the mechanical principle involved in the construction of a micrometer is that of a screw free to move in a fixed nut4 ,an opening to receive the work to be measured is provided by the backward movement of the thimble which turns the screw and the size of the opening is indicated by the graduations on the barrel4 ,illustration3 ,fig4 #agh4--,standard ,forms of ,micrometer ,caliper for ,external ,measurements4 ,the article to be measured is placed between the anvil and spindle1 the frame being held stationary while the thimble is revolved by the thumb and finger4 ,the pitch of the screw thread on the concealed part of the spindle is #dj to an inch4 ,one complete revolution of the spindle1 therefore1 moves it longitudinally one-fortieth1 or twenty-five thousandths of an inch4 ,as will be evident from the development of the scale on the barrel of the inch micrometer1 the sleeve is marked with forty lines to the inch1 each of these lines indicating twenty-five thousandths4 ,the thimble has a beveled edge which is graduated into twenty-five parts4 ,when the instrument is closed the graduation on the beveled edge of the thimble marked #j should correspond to the #j line on the barrel4 ,if the micrometer is rotated one full turn the opening between the spindle and anvil will be 4#jbe inch4 ,if the thimble is turned only one graduation1 or one twenty-fifth of a revolution1 the opening between the spindle and anvil will be increased only by 4#jja inch 7one-thousandth of an inch74 ,as many of the dimensions of the airplane parts1 especially of those of foreign manufacture or such parts as ball and roller bearings1 are based on the metric system1 the competent repairman should possess both inch and metric micrometers in order to avoid continual reference to a table of metric equivalents4 ,with a metric micrometer there are fifty graduations on the barrel1 these representing 4#ja of a millimeter1 or approximately 4#jjd inch4 ,one full turn of the barrel means an increase of half a millimeter1 or 4#ej mm4 7fifty one-hundredths74 ,as it takes two turns to augment the space between the anvil and the stem by increments of one millimeter1 it will be evident that it would not be difficult to divide the spaces on the metric micrometer thimble in halves by the eye1 and thus the average workman can measure to 4#jjjb inch plus or minus without difficulty4 ,as set in the illustration1 the metric micrometers show a space of #ac4e mm41 or about one millimeter more than half an inch4 ,the inch micrometer shown is set to five-tenths or five hundred one-thousandths or one-half inch4 ,a little study of the foregoing matter will make it easy to understand the action of either the inch or metric micrometer4 ,both of the micrometers shown have a small knurled knob at the end of the barrel4 ,this controls the ratchet stop1 which is a device that permits a ratchet to slip by a pawl when more than a certain amount of pressure is applied1 thereby preventing the measuring spindle from turning further and perhaps springing the instrument4 ,a simple rule that can be easily memorized for reading the inch micrometer is to multiply the number of vertical divisions on the sleeve by #be and add to that the number of divisions on the bevel of the thimble reading from the zero to the line which coincides with the horizontal line on the sleeve4 ,for example3 if there are ten divisions visible on the sleeve1 multiply this number by #be1 then add the number of divisions shown on the bevel of the thimble1 which is #aj4 ,the micrometer is therefore opened #aj x #be equals #bej plus #aj equals #bfj thousandths4 ,micrometers are made in many sizes1 ranging from those having a maximum opening of one inch to special large forms that will measure forty or more inches4 ,while it is not to be expected that the repairman will have use for the big sizes1 if a caliper having a maximum opening of six inches is provided with a number of extension rods enabling one to measure smaller objects1 practically all of the measuring needed in repairing engine parts can be made accurately4 ,two or three smaller micrometers having a maximum range of two or three inches will also be found valuable1 as most of the measurements will be made with these tools which will be much easier to handle than the larger sizes4 ,,typical ,,tool ,,outfits ,the equipment of tools necessary for repairing airplane engines depends entirely upon the type of the power plant and while the common hand tools can be used on all forms1 the work is always facilitated by having special tools adapted for reaching the nuts and screws that would be hard to reach otherwise4 ,special spanners and socket wrenches are very desirable4 ,then again1 the nature of the work to be performed must be taken into consideration4 ,rebuilding or overhauling an engine calls for considerably more tools than are furnished for making field repairs or minor adjustments4 ,a complete set of tools supplied to men working on ,curtiss ,,ox-#b engines and ,,jn-#d training biplanes is shown at ,fig4 #agi4 ,the tools are placed in a special box provided with a hinged cover and are arranged in the systematic manner outlined4 ,the various tools and supplies shown are3 ,a1 hacksaw blades2 ,b1 special socket wrenches for engine bolts and nuts2 ,c1 ball pein hammers1 four sizes2 ,d1 five assorted sizes of screw drivers ranging from very long for heavy work to short and small for fine work2 ,e1 seven pairs of pliers including combination in three sizes1 two pairs of cutting pliers and one round nose2 ,f1 two split pin extractors and spreaders2 ,g1 wrench set including three adjustable monkey wrenches1 one ,stillson or pipe wrench1 five sizes adjustable end wrenches and ten double end ,s wrenches2 ,h1 set of files1 including flat1 three cornered and half round2 ,i1 file brush2 ,j1 chisel and drift pin2 ,k1 three small punches or drifts2 ,l1 hacksaw frame2 ,m1 soldering copper2 ,n1 special spanners for propeller retaining nuts2 ,o1 special spanners2 ,p1 socket wrenches1 long handle2 ,q1 long handle1 stiff bristle brushes for cleaning motor2 ,r1 gasoline blow torch2 ,s1 hand drill2 ,t1 spools of safety wire2 ,u1 flash lamp2 ,v1 special puller and castle wrenches2 ,w1 oil can2 ,x1 large adjustable monkey wrench2 ,y1 washer and gasket cutter2 ,z1 ball of heavy twine4 ,in addition to the tools1 various supplies1 such as soldering acid1 solder1 shellac1 valve grinding compound1 bolts and nuts1 split pins1 washers1 wood screws1 etc41 are provided4 ,illustration3 ,fig4 #agi4--,special ,tools for ,maintaining ,curtiss ,,ox-#b ,motor ,used in ,curtiss ,,jn-#d ,training ,biplane4 ,,special ,,hall-,,scott ,,tools ,,no4 ,,tool ,,directions ,,for ,,use #a ,engine hoisting hook1 #f-;cylinder ,hook under cam-shaft housing1 when hoisting engine4 #b ,engine hoisting hook1 #d-;cylinder ,hook under cam-shaft housing1 when hoisting engine4 #c ,water plug wrench ,for use on water plugs on top and end of cylinders4 #d ,vertical shaft flange puller ,for pulling lower pinion shaft flange from shaft4 7,used on ,a-#e and ,a-#g engines only47 #e ,oil gun ,for general lubrication use4 #f ,magneto gear puller ,for pulling magneto gears from magneto shaft4 #g ,socket wrench1 #a_/d ,a4,l4,a4,m4 ,for use on bolts and nuts on crank cases4 #h ,socket wrench1 #a_/d ,a4,l4,a4,m ,for use on crank cases and magneto gear housings4 #i ,socket wrench1 #a_/d ,a4,l4,a4,m4 ,for use on magneto gear housings4 #aj ,socket wrench1 #c_/h standard ,for bolts and nuts which fasten magnetos to crank-case4 #aa ,socket wrench1 #a_/d ,a4,l4,a4,m4 ,for use on magneto gear housings4 #ab ,vertical shaft gear puller ,for removing water pump and magneto drive gear4 #ac ,brace and facing cutter ,for facing lugs on cylinders for cylinder hold down stud washers4 #ad ,handle for brace ,use with brace4 #ae ,valve grinding brace ,for grinding in valves4 #af ,socket wrench base1 #c_/h ,a4,l4,a4,m4 ,for thrust bearing cap screws4 #ag ,brace and facing cutter1 #e_/af ,for facing lugs on rocker arm ,a4,l4,a4,m4 covers4 #ah ,valve grinding screw driver ,for grinding in valves4 #ai ,valve spring tool ,for putting on and taking off valve springs4 #bj ,block-valve spring tool ,for use with valve spring tool4 #ba ,socket wrench1 #e_/h ,a4,l4,a4,m4 ,for main bearing nuts4 #bb ,socket wrench1 #a_/d ,a4,l4,a4,m4 ,for use on cam-shaft housing4 #bc ,socket wrench1 #e_/af ,a4,l4,a4,m4 ,for cam-shaft housing hold down stud nuts4 #bd ,socket wrench1 #a_/b ,a4,l4,a4,m4 ,for cylinder hold down stud nuts4 #be ,socket wrench1 #e_/af ,a4,l4,a4,m4 ,for carburetor and water pump bolts and nuts4 #bf ,socket wrench1 #e_/af ,a4,l4,a4,m4 ,for carburetor and water pump bolts and nuts4 #bg ,socket wrench ,for use on carburetor jets4 #bh ,magneto screw driver ,for general magneto use4 #bi ,brass bar1 #a diameter x #g long ,for driving piston pins from pistons4 #cj ,hack saw ,for general use4 #ca ,oil can ,for cam-shaft housing lubrication4 #cb ,gasoline or distillate can ,for priming or other use4 #cc ,oil can ,for magneto gear lubrication4 #cd ,shellac can ,for rubber hose connections and gaskets4 #ce ,magneto cleaner ,for use on magnetos4 #cf ,clamps ,for holding cylinder hold down studs1 when fitting main bearings4 #cg ,piston guards ,for use in pistons1 when out of engine1 to protect them4 #ch ,screw driver ,for general use4 #ci ,vertical shaft clamps ,for clamping vertical shaft flanges1 when timing engine4 #dj ,thrust adjusting nut wrench ,for adjusting propeller thrust bearing4 #da ,stuffing box spanner wrench ,for adjusting stuffing box nut on vertical shaft4 #db ,water pump spanner wrench ,for adjusting water pump stuffing nut4 #dc ,wrench ,for use on cylinder relief cocks and cylinder priming cocks4 #dd ,hose clamp wrench ,for use on hose clamps4 #de ,scraper ,for cleaning piston ring grooves on pistons4 #df ,crank-shaft nut wrench ,for adjusting crank-shaft nut4 #dg ,spark-plug wrench ,for putting in and taking out spark-plugs in cylinders4 #dh ,timing disc 7single disc7 ,for use on crank-shaft to time engine4 ,specify type motor disc should be made for4 ,if double disc is required1 specify the two types of motors the disc is to be made for4 ,double disc4 #di ,main bearing scraper ,for scraping in bearings4 #ej ,cylinder carbon scraper ,for removing carbon from heads of cylinders4 #ea ,valve seating tool ,for seating valves in cylinder heads4 #eb ,scraper1 small ,for general bearing use4 #ec ,scraper1 large ,for general bearing use4 #ed ,crank-shaft flange puller ,for pulling crank-shaft flange from crank-shaft4 #ee ,piston and connecting rod racks4 #ef ,main bearing stud nuts and shim rack4 #eg ,main bearing board rack4 #eh ,rocker arm and cover rack4 ,the special tools and fixtures recommended by the ,hall-,scott ,company for work on their engines are clearly shown at ,fig4 #ahj4 ,all tools are numbered and their uses may be clearly understood by reference to the illustration and explanatory list given on pages #daj and #daa4 ,,overhauling ,,airplane ,,engines ,after an airplane engine has been in use for a period ranging from #fj to #hj hours1 depending upon the type1 it is necessary to give it a thorough overhauling before it is returned to service4 ,to do this properly1 the engine is removed from the fuselage and placed on a special supporting stand1 such as shown at ,fig4 #aha1 so it can be placed in any position and completely dismantled4 ,with a stand of this kind it is as easy to work on the bottom of the engine as on the top and every part can be instantly reached4 ,the crank-case shown in place in illustration is in a very convenient position for scraping in the crank-shaft bearings4 ,illustration3 ,fig4 #ahj4--,special ,tools and ,appliances to ,facilitate ,overhauling ,work on ,hall-,scott ,airplane ,engines4 ,in order to look over the parts of an engine and to restore the worn or defective components it is necessary to take the engine entirely apart1 as it is only when the power plant is thoroughly dismantled that the parts can be inspected or measured to determine defects or wear4 ,if one is not familiar with the engine to be inspected1 even though the work is done by a repairman of experience1 it will be found of value to take certain precautions when dismantling the engine in order to insure that all parts will be replaced in the same position they occupied before removal4 ,there are a number of ways of identifying the parts1 one of the simplest and surest being to mark them with steel numbers or letters or with a series of center punch marks in order to retain the proper relation when reassembling4 ,this is of special importance in connection with dismantling multiple cylinder engines as it is vital that pistons1 piston rings1 connecting rods1 valves1 and other cylinder parts be always replaced in the same cylinder from which they were removed1 because it is uncommon to find equal depreciation in all cylinders4 ,some repairmen use small shipping tags to identify the pieces4 ,this can be criticised because the tags may become detached and lost and the identity of the piece mistaken4 ,if the repairing is being done in a shop where other engines of the same make are being worked on1 the repairman should be provided with a large chest fitted with a lock and key in which all of the smaller parts1 such as rods1 bolts and nuts1 valves1 gears1 valve springs1 cam-shafts1 etc41 may be stored to prevent the possibility of confusion with similar members of other engines4 ,all parts should be thoroughly cleaned with gasoline or in the potash kettle as removed1 and wiped clean and dry4 ,this is necessary to show wear which will be evidenced by easily identified indications in cases where the machine has been used for a time1 but in others1 the deterioration can only be detected by delicate measuring instruments4 ,illustration3 ,fig4 #aha4--,special ,stand to ,make ,motor ,overhauling ,work ,easier4 ,in taking down a motor the smaller parts and fittings such as spark-plugs1 manifolds and wiring should be removed first4 ,then the more important members such as cylinders may be removed from the crank-case to give access to the interior and make possible the examination of the pistons1 rings and connecting rods4 ,after the cylinders are removed the next operation is to disconnect the connecting rods from the crank-shaft and to remove them and the pistons attached as a unit4 ,then the crank-case is dismembered1 in most cases by removing the bottom half or oil sump1 thus exposing the main bearings and crank-shaft4 ,the first operation is the removal of the inlet and exhaust manifolds4 ,in some cases the manifolds are cored integral with the cylinder head casting and it is merely necessary to remove a short pipe leading from the carburetor to one inlet opening and the exhaust pipe from the outlet opening common to all cylinders4 ,in order to remove the carburetor it is necessary to shut off the gasoline supply at the tank and to remove the pipe coupling at the float chamber4 ,it is also necessary to disconnect the throttle operating rod4 ,after the cylinders are removed and before taking the crank-case apart it is well to remove the water pump and magneto4 ,the wiring on most engines of modern development is carried in conduits and usually releasing two or three minor fastenings will permit one to take off the plug wiring as a unit4 ,the wire should be disconnected from both spark-plugs and magneto distributor before its removal4 ,when the cylinders are removed1 the pistons1 piston rings1 and connecting rods are clearly exposed and their condition may be readily noticed4 ,before disturbing the arrangement of the timing gears1 it is important that these be marked so that they will be replaced in exactly the same relation as intended by the engine designer4 ,if the gears are properly marked the valve timing and magneto setting will be undisturbed when the parts are replaced after overhauling4 ,with the cylinders off1 it is possible to ascertain if there is any undue wear present in the connecting rod bearings at either the wrist pin or crank-pin ends and also to form some idea of the amount of carbon deposits on the piston top and back of the piston rings4 ,any wear of the timing gears can also be determined4 ,the removal of the bottom plate of the engine enables the repairman to see if the main bearings are worn unduly4 ,often bearings may be taken up sufficiently to eliminate all looseness4 ,in other cases they may be worn enough so that careful refitting will be necessary4 ,where the crank-case is divided horizontally into two portions1 the upper one serving as an engine base to which the cylinders and in fact all important working parts are attached1 the lower portion performs the functions of an oil container and cover for the internal mechanism4 ,this is the construction generally followed4 ,,defects ,,in ,,cylinders ,after the cylinders have been removed and stripped of all fittings1 they should be thoroughly cleaned and then carefully examined for defects4 ,the interior or bore should be looked at with a view of finding score marks1 grooves1 cuts or scratches in the interior1 because there are many faults that may be ascribed to depreciation at this point4 ,the cylinder bore may be worn out of round1 which can only be determined by measuring with an internal caliper or dial indicator even if the cylinder bore shows no sign of wear4 ,the flange at the bottom of the cylinder by which it is held to the engine base may be cracked4 ,the water jacket wall may have opened up due to freezing of the jacket water at some time or other or it may be filled with scale and sediment due to the use of impure cooling water4 ,the valve seat may be scored or pitted1 while the threads holding the valve chamber cap may be worn so that the cap will not be a tight fit4 ,the detachable head construction makes it possible to remove that member and obtain ready access to the piston tops for scraping out carbon without taking the main cylinder portion from the crank-case4 ,when the valves need grinding the head may be removed and carried to the bench where the work may be performed with absolute assurance that none of the valve grinding compound will penetrate into the interior of the cylinder as is sometimes unavoidable with the ,i-head cylinder4 ,if the cylinder should be scored1 the water jacket and combustion head may be saved and a new cylinder casting purchased at considerably less cost than that of the complete unit cylinder4 ,the detachable head construction has only recently been applied on airplane engines1 though it was one of the earliest forms of automobile engine construction4 ,in the early days it was difficult to procure gaskets or packings that would be both gas and water tight4 ,the sheet asbestos commonly used was too soft and blew out readily4 ,besides a new gasket had to be made every time the cylinder head was removed4 ,woven wire and asbestos packings impregnated with rubber1 red lead1 graphite and other filling materials were more satisfactory than the soft sheet asbestos1 but were prone to burn out if the water supply became low4 ,materials such as sheet copper or brass proved to be too hard to form a sufficiently yielding packing medium that would allow for the inevitable slight inaccuracies in machining the cylinder head and cylinder4 ,the invention of the copper-asbestos gasket1 which is composed of two sheets of very thin1 soft copper bound together by a thin edging of the same material and having a piece of sheet asbestos interposed solved this problem4 ,copper-asbestos packings form an effective seal against leakage of water and a positive retention means for keeping the explosion pressure in the cylinder4 ,the great advantage of the detachable head is that it permits of very easy inspection of the piston tops and combustion chamber and ready removal of carbon deposits4 ,,carbon ,,deposits1 ,,their ,,cause ,,and ,,prevention ,most authorities agree that carbon is the result of imperfect combustion of the fuel and air mixture as well as the use of lubricating oils of improper flash point4 ,lubricating oils that work by the piston rings may become decomposed by the great heat in the combustion chamber1 but at the same time one cannot blame the lubricating oil for all of the carbon deposits4 ,there is little reason to suspect that pure petroleum oil of proper body will deposit excessive amounts of carbon1 though if the oil is mixed with castor oil1 which is of vegetable origin1 there would be much carbon left in the interior of the combustion chamber4 ,fuel mixtures that are too rich in gasoline also produce these undesirable accumulations4 ,a very interesting chemical analysis of a sample of carbon scraped from the interior of a motor vehicle engine shows that ordinarily the lubricant is not as much to blame as is commonly supposed4 ,the analysis was as follows3 ,oil #ad4c ,other combustible matter #ag4i ,sand1 clay1 etc4 #bd4h ,iron oxide #bd4e ,carbonate of lime #h4i ,other constituents #i4f ,it is extremely probable that the above could be divided into two general classes1 these being approximately #cb4b oil and combustible matter and a much larger proportion1 or #fg4h of earthy matter4 ,the presence of such a large percentage of earthy matter is undoubtedly due to the impurities in the air1 such as road dust which has been sucked in through the carburetor4 ,the fact that over #ag of the matter which is combustible was not of an oily nature lends strong support to this view4 ,there would not be the amount of earthy material present in the carbon deposits of an airplane engine as above stated because the air is almost free from dust at the high altitudes planes are usually flown4 ,one could expect to find more combustible and less earthy matter and the carbon would be softer and more easily removed4 ,it is very good practice to provide a screen on the air intake to reduce the amounts of dust sucked in with the air as well as observing the proper precautions relative to supplying the proper quantities of air to the mixture and of not using any more oil than is needed to insure proper lubrication of the internal mechanism4 ,,use ,,of ,,carbon ,,scrapers ,it is not unusual for one to hear an aviator complain that the engine he operates is not as responsive as it was when new after he has run it but relatively few hours4 ,there does not seem to be anything actually wrong with the engine1 yet it does not respond readily to the throttle and is apt to overheat4 ,while these symptoms denote a rundown condition of the mechanism1 the trouble is often due to nothing more serious than accumulations of carbon4 ,the remedy is the removal of this matter out of place4 ,the surest way of cleaning the inside of the motor thoroughly is to remove the cylinders1 if these members are cast integrally with the head or of removing the head member if that is a separate casting1 to expose all parts4 ,in certain forms of cylinders1 especially those of the ,l form1 it is possible to introduce simple scrapers down through the valve chamber cap holes and through the spark-plug hole if this component is placed in the cylinder in some position that communicates directly to the interior of the cylinder or to the piston top4 ,no claim can be made for originality or novelty of this process as is has been used for many years on large stationary engines4 ,the first step is to dismantle the inlet and exhaust piping and remove the valve caps and valves1 although if the deposit is not extremely hard or present in large quantities one can often manipulate the scrapers in the valve cap openings without removing either the piping or the valves4 ,commencing with the first cylinder1 the crank-shaft is turned till the piston is at the top of its stroke1 then the scraper may be inserted1 and the operation of removing the carbon started by drawing the tool toward the opening4 ,as this is similar to a small hoe1 the cutting edge will loosen some of the carbon and will draw it toward the opening4 ,a swab is made of a piece of cloth or waste fastened at the end of a wire and well soaked in kerosene to clean out the cylinder4 ,when available1 an electric motor with a length of flexible shaft and a small circular cleaning brush having wire bristles can be used in the interior of the engine4 ,the electric motor need not be over one-eighth horse-power running #a1bjj to #a1fjj ,r4 ,p4 ,m41 and the wire brush must1 of course1 be of such size that it can be easily inserted through the valve chamber cap4 ,the flexible shaft permits one to reach nearly all parts of the cylinder interior without difficulty and the spreading out and flattening of the brush insures that considerable surface will be covered by that member4 ,,burning ,,out ,,carbon ,,with ,,oxygen ,a process of recent development that gives very good results in removing carbon without disassembling the motor depends on the process of burning out that material by supplying oxygen to support the combustion and to make it energetic4 ,a number of concerns are already offering apparatus to accomplish this work1 and in fact any shop using an autogenous welding outfit may use the oxygen tank and reducing valve in connection with a simple special torch for burning the carbon4 ,results have demonstrated that there is little danger of damaging the motor parts1 and that the cost of oxygen and labor is much lower than the old method of removing the cylinders and scraping the carbon out1 as well as being very much quicker than the alternative process of using carbon solvent4 ,the only drawback to this system is that there is no absolute insurance that every particle of carbon will be removed1 as small protruding particles may be left at points that the flame does not reach and cause pre-ignition and consequent pounding1 even after the oxygen treatment4 ,it is generally known that carbon will burn in the presence of oxygen1 which supports combustion of all materials1 and this process takes advantage of this fact and causes the gas to be injected into the combustion chamber over a flame obtained by a match or wax taper4 ,illustration3 ,fig4 #ahb4--,showing ,where ,carbon ,deposits ,collect in ,engine ,combustion ,chamber1 and ,how to ,burn ,them ,out with the ,aid of ,oxygen4 ,a--,special ,torch4 ,b--,torch ,coupled to ,oxygen ,tank4 ,c--,torch in ,use4 ,it is suggested by those favoring this process that the night before the oxygen is to be used the engine be given a conventional kerosene treatment4 ,a half tumbler full of this liquid or of denatured alcohol is to be poured into each cylinder and permitted to remain there over night4 ,as a precaution against fire1 the gasoline is shut off from the carburetor before the torch is inserted in the cylinder and the motor started so that the gasoline in the pipe and carburetor float chamber will be consumed4 ,work is done on one cylinder at a time4 ,a note of caution was recently sounded by a prominent spark-plug manufacturer recommending that the igniter member be removed from the cylinder in order not to injure it by the heat developed4 ,the outfits on the market consist of a special torch having a trigger controlled valve and a length of flexible tubing such as shown at ,fig4 #ahb1 ,a1 and a regulating valve and oxygen tank as shown at ,b4 ,the gauge should be made to register about twelve pounds pressure4 ,the method of operation is very simple and is outlined at ,c4 ,the burner tube is placed in the cylinder and the trigger valve is opened and the oxygen permitted to circulate in the combustion chamber4 ,a lighted match or wax taper is dropped in the chamber and the injector tube is moved around as much as possible so as to cover a large area4 ,the carbon takes fire and burns briskly in the presence of the oxygen4 ,the combustion of the carbon is accompanied by sparks and sometimes by flame if the deposit is of an oily nature4 ,once the carbon begins to burn the combustion continues without interruption as long as the oxygen flows into the cylinder4 ,full instructions accompany each outfit and the amount of pressure for which the regulator should be set depends upon the design of the torch and the amount of oxygen contained in the storage tank4 ,,repairing ,,scored ,,cylinders ,if the engine has been run at any time without adequate lubrication1 one or more of the cylinders may be found to have vertical scratches running up and down the cylinder walls4 ,the depth of these will vary according to the amount of time the cylinder was without lubrication1 and if the grooves are very deep the only remedy is to purchase a new member4 ,of course1 if sufficient stock is available in the cylinder walls1 the cylinders may be rebored and new pistons which are oversize1 i4e41 larger than standard1 may be fitted4 ,where the scratches are not deep they may be ground out with a high speed emery wheel or lapped out if that type of machine is not available4 ,wrist pins have been known to come loose1 especially when these are retained by set screws that are not properly locked1 and as wrist-pins are usually of hardened steel it will be evident that the sharp edge of that member can act as a cutting tool and make a pronounced groove in the cylinder4 ,cylinder grinding is a job that requires skilled mechanics1 but may be accomplished on any lathe fitted with an internal grinding attachment4 ,while automobile engine cylinders usually have sufficient wall thickness to stand reboring1 those of airplane engines seldom have sufficient metal to permit of enlarging the bore very much by a boring tool4 ,a few thousandths of an inch may be ground out without danger1 however4 ,an airplane engine cylinder with deep grooves must be scrapped as a general rule4 ,where the grooves in the cylinder are not deep or where it has warped enough so the rings do not bear equally at all parts of the cylinder bore1 it is possible to obtain a fairly accurate degree of finish by a lapping process in which an old piston is coated with a mixture of fine emery and oil and is reciprocated up and down in the cylinder as well as turned at the same time4 ,this may be easily done by using a dummy connecting rod having only a wrist pin end boss1 and of such size at the other end so that it can be held in the chuck of a drill press4 ,the cylinder casting is firmly clamped on the drill press table by suitable clamping blocks1 and a wooden block is placed in the combustion chamber to provide a stop for the piston at its lower extreme position4 ,the back gears are put in and the drill chuck is revolved slowly4 ,all the while that the piston is turning the drill chuck should be raised up and down by the hand feed lever1 as the best results are obtained when the lapping member is given a combination of rotary and reciprocating motion4 ,,valve ,,removal ,,and ,,inspection ,one of the most important parts of the gasoline engine and one that requires frequent inspection and refitting to keep in condition1 is the mushroom or poppet valve that controls the inlet and exhaust gas flow4 ,in overhauling it is essential that these valves be removed from their seatings and examined carefully for various defects which will be enumerated at proper time4 ,the problem that concerns us now is the best method of removing the valve4 ,these are held against the seating in the cylinder by a coil spring which exerts its pressure on the cylinder casting at the upper end and against a suitable collar held by a key at the lower end of the valve stem4 ,in order to remove the valve it is necessary to first compress the spring by raising the collar and pulling the retaining key out of the valve stem4 ,many forms of valve spring lifters have been designed to permit ready removal of the valves4 ,when the cylinder is of the valve in-the-head form1 the method of valve removal will depend entirely upon the system of cylinder construction followed4 ,in the ,sturtevant cylinder design it is possible to remove the head from the cylinder castings and the valve springs may be easily compressed by any suitable means when the cylinder head is placed on the work bench where it can be easily worked on4 ,the usual method is to place the head on a soft cloth with the valves bearing against the bench4 ,the valve springs may then be easily pushed down with a simple forked lever and the valve stem key removed to release the valve spring collar4 ,in the ,curtiss ,,ox-#b 7see ,fig4 #ahb-a_/b7 and ,hall-,scott engines it is not possible to remove the valves without taking the cylinder off the crank-case1 because the valve seats are machined directly in the cylinder head and the valve domes are cast integrally with the cylinder4 ,this means that if the valves need grinding the cylinder must be removed from the engine base to provide access to the valve heads which are inside of that member1 and which cannot be reached from the outside as is true of the ,l-cylinder construction4 ,in the ,curtiss ,,vx engines1 the valves are carried in detachable cages which may be removed when the valves need attention4 ,illustration3 ,fig4 #ahb-a_/b4--,part ,sectional ,view1 ,showing ,valve ,arrangement in ,cylinder of ,curtiss ,,ox-#b ,aviation ,engine4 ,,reseating ,,and ,,truing ,,valves ,much has been said relative to valve grinding1 and despite the mass of information given in the trade prints it is rather amusing to watch the average repairman or the engine user who prides himself on maintaining his own motor performing this essential operation4 ,the common mistakes are attempting to seat a badly grooved or pitted valve head on an equally bad seat1 which is an almost hopeless job1 and of using coarse emery and bearing down with all one's weight on the grinding tool with the hope of quickly wearing away the rough surfaces4 ,the use of improper abrasive material is a fertile cause of failure to obtain a satisfactory seating4 ,valve grinding is not a difficult operation if certain precautions are taken before undertaking the work4 ,the most important of these is to ascertain if the valve head or seat is badly scored or pitted4 ,if such is found to be the case no ordinary amount of grinding will serve to restore the surfaces4 ,in this event the best thing to do is to remove the valve from its seating and to smooth down both the valve head and the seat in the cylinder before attempt is made to fit them together by grinding4 ,another important precaution is to make sure that the valve stem is straight1 and that the head is not warped out of shape4 ,illustration3 ,fig4 #ahc4--,tools for ,restoring ,valve ,head and ,seats4 ,a number of simple tools is available at the present time for reseating valves1 these being outlined at ,fig4 #ahc4 ,that shown at ,a is a simple fixture for facing off the valve head4 ,the stem is supported by suitable bearings carried by the body or shank of the tool1 and the head is turned against an angularly disposed cutter which is set for the proper valve seat angle4 ,the valve head is turned by a screw-driver1 the amount of stock removed from the head depending upon the location of the adjusting screw4 ,care must be taken not to remove too much metal1 only enough being taken off to remove the most of the roughness4 ,valves are made in two standard tapers1 the angle being either #de or #fj degrees4 ,it is imperative that the cutter blade be set correctly in order that the bevel is not changed4 ,a set of valve truing and valve-seat reaming cutters is shown at ,fig4 #ahc1 ,b4 ,this is adaptable to various size valve heads1 as the cutter blade ,d may be moved to correspond to the size of the valve head being trued up4 ,these cutter blades are made of tool steel and have a bevel at each end1 one at #de degrees1 the other at #fj degrees4 ,the valve seat reamer shown at ,g will take any one of the heads shown at ,f4 ,it will also take any one of the guide bars shown at ,h4 ,the function of the guide bars is to fit the valve stem bearing in order to locate the reamer accurately and to insure that the valve seat is machined concentrically with its normal center4 ,another form of valve seat reamer and a special wrench used to turn it is shown at ,c4 ,the valve head truer shown at ,fig4 #ahc1 ,d1 is intended to be placed in a vise and is adaptable to a variety of valve head sizes4 ,the smaller valves merely fit deeper in the conical depression4 ,the cutter blade is adjustable and the valve stem is supported by a simple self-centering bearing4 ,in operation it is intended that the valve stem1 which protrudes through the lower portion of the guide bearing1 shall be turned by a drill press or bit stock while the valve head is set against the cutter by pressure of a pad carried at the end of a feed screw which is supported by a hinged bridge member4 ,this can be swung out of place as indicated to permit placing the valve head against the cutter or removing it4 ,as the sizes of valve heads and stems vary considerably a ,universal valve head truing tool must have some simple means of centering the valve stem in order to insure concentric machining of the valve head4 ,a valve head truer which employs an ingenious method of guiding the valve stem is shown at ,fig4 #ahc1 ,e4 ,the device consists of a body portion1 ,b1 provided with an external thread at the top on which the cutter head1 ,a1 is screwed4 ,a number of steel balls1 ,c1 are carried in the grooves which may be altered in size by the adjustment nut1 ,f1 which screws in the bottom of the body portion1 ,b4 ,as the nut ,f is screwed in against the spacer member ,e1 the ,v-grooves are reduced in size and the steel balls1 ,c1 are pressed out in contact with the valve stem4 ,as the circle or annulus is filled with balls in both upper and lower portions the stem may be readily turned because it is virtually supported by ball bearing guides4 ,when a larger valve stem is to be supported1 the adjusting nut ,f1 is screwed out which increases the size of the grooves and permits the balls1 ,c1 to spread out and allow the larger stem to be inserted4 ,,valve ,,grinding ,,processes ,mention has been previously made of the importance of truing both valve head and seat before attempt is made to refit the parts by grinding4 ,after smoothing the valve seat the next step is to find some way of turning the valve4 ,valve heads are usually provided with a screw-driver slot passing through the boss at the top of the valve or with two drilled holes to take a forked grinding tool4 ,a combination grinding tool has been devised which may be used when either the two drilled holes or the slotted head form of valve is to be rotated4 ,this consists of a special form of screw driver having an enlarged boss just above the blade1 this boss serving to support a ,u-shape piece which can be securely held in operative position by the clamp screw or which can be turned out of the way if the screw driver blade is to be used4 ,as it is desirable to turn the valve through a portion of a revolution and back again rather than turning it always in the same direction1 a number of special tools has been designed to make this oscillating motion possible without trouble4 ,a simple valve grinding tool is shown at ,fig4 #ahd1 ,c4 ,this consists of a screw-driver blade mounted in a handle in such a way that the end may turn freely in the handle4 ,a pinion is securely fastened to the screw-driver blade shank1 and is adapted to fit a race provided with a wood handle and guided by a bent bearing member securely fastened to the screw-driver handle4 ,as the rack is pushed back and forth the pinion must be turned first in one direction and then in the other4 ,illustration3 ,fig4 #ahd4--,tools and ,processes ,utilized in ,valve ,grinding4 ,a valve grinding tool patterned largely after a breast drill is shown at ,fig4 #ahd1 ,d4 ,this is worked in such a manner that a continuous rotation of the operating crank will result in an oscillating movement of the chuck carrying the screw-driver blade4 ,the bevel pinions which are used to turn the chuck are normally free unless clutched to the chuck stem by the sliding sleeve which must turn with the chuck stem and which carries clutching members at each end to engage similar members on the bevel pinions and lock these to the chuck stem1 one at a time4 ,the bevel gear carries a cam-piece which moves the clutch sleeve back and forth as it revolves4 ,this means that the pinion giving forward motion of the chuck is clutched to the chuck spindle for a portion of a revolution of the gear and clutch sleeve is moved back by the cam and clutched to the pinion giving a reverse motion of the chuck during the remainder of the main drive gear revolution4 ,it sometimes happens that the adjusting screw on the valve lift plunger or the valve lift plunger itself when ,l head cylinders are used does not permit the valve head to rest against the seat4 ,it will be apparent that unless a definite space exists between the end of the valve stem and the valve lift plunger that grinding will be of little avail because the valve head will not bear properly against the abrasive material smeared on the valve seat4 ,the usual methods of valve grinding are clearly outlined at ,fig4 #ahd4 ,the view at the left shows the method of turning the valve by an ordinary screw driver and also shows a valve head at ,a1 having both the drilled holes and the screw-driver slot for turning the member and two special forms of fork-end valve grinding tools4 ,in the sectional view shown at the right1 the use of the light spring between the valve head and the bottom of the valve chamber to lift the valve head from the seat whenever pressure on the grinding tool is released is clearly indicated4 ,it will be noted also that a ball of waste or cloth is interposed in the passage between the valve chamber and the cylinder interior to prevent the abrasive material from passing into the cylinder from the valve chamber4 ,when a bitstock is used1 instead of being given a true rotary motion the chuck is merely oscillated through the greater part of the circle and back again4 ,it is necessary to lift the valve from its seat frequently as the grinding operation continues2 this is to provide an even distribution of the abrasive material placed between the valve head and its seat4 ,only sufficient pressure is given to the bitstock to overcome the uplift of the spring and to insure that the valve will be held against the seat4 ,where the spring is not used it is possible to raise the valve from time to time with the hand which is placed under the valve stem to raise it as the grinding is carried on4 ,it is not always possible to lift the valve in this manner when the cylinders are in place on the engine base owing to the space between the valve lift plunger and the end of the valve stem4 ,in this event the use of the spring as shown in sectional view will be desirable4 ,the abrasive generally used is a paste made of medium or fine emery and lard oil or kerosene4 ,this is used until the surfaces are comparatively smooth1 after which the final polish or finish is given with a paste of flour emery1 grindstone dust1 crocus1 or ground glass and oil4 ,an erroneous impression prevails in some quarters that the valve head surface and the seating must have a mirror-like polish4 ,while this is not necessary it is essential that the seat in the cylinder and the bevel surface of the head be smooth and free from pits or scratches at the completion of the operation4 ,all traces of the emery and oil should be thoroughly washed out of the valve chamber with gasoline before the valve mechanism is assembled and in fact it is advisable to remove the old grinding compound at regular intervals1 wash the seat thoroughly and supply fresh material as the process is in progress4 ,the truth of seatings may be tested by taking some ,prussian blue pigment and spreading a thin film of it over the valve seat4 ,the valve is dropped in place and is given about one-eighth turn with a little pressure on the tool4 ,if the seating is good both valve head and seat will be covered uniformly with color4 ,if high spots exist1 the heavy deposit of color will show these while the low spots will be made evident because of the lack of pigment4 ,the grinding process should be continued until the test shows an even bearing of the valve head at all points of the cylinder seating4 ,when the valves are held in cages it is possible to catch the cage in a vise and to turn the valve in any of the ways indicated4 ,it is much easier to clean off the emery and oil and there is absolutely no danger of getting the abrasive material in the cylinder if the construction is such that the valve cage or cylinder head member carrying the valve can be removed from the cylinder4 ,when valves are held in cages1 the tightness of the seat may be tested by partially filling the cage with gasoline and noticing how much liquid oozes out around the valve head4 ,the degree of moisture present indicates the efficacy of the grinding process4 ,the valves of ,curtiss ,,ox-#b cylinders are easily ground in by using a simple fixture or tool and working from the top of the cylinder instead of from the inside4 ,a tube having a bore just large enough to go over the valve stem is provided with a wooden handle or taped at one end and a hole of the same size as that drilled through the valve stem is put in at the other4 ,to use1 the open end of the tube is pushed over the valve stem and a split pin pushed through the tube and stem4 ,the valve may be easily manipulated and ground in place by oscillating in the customary manner4 ,,depreciation ,,in ,,valve ,,operating ,,systems ,there are a number of points to be watched in the valve operating system because valve timing may be seriously interfered with if there is much lost motion at the various bearing points in the valve lift mechanism4 ,the two conventional methods of opening valves are shown at ,fig4 #ahe4 ,that at ,a is the type employed when the valve cages are mounted directly in the head1 while the form at ,b is the system used when the valves are located in a pocket or extension of the cylinder casting as is the case if an ,l1 or ,t-head cylinder is used4 ,it will be evident that there are several points where depreciation may take place4 ,the simplest form is that shown at ,b1 and even on this there are five points where lost motion may be noted4 ,the periphery of the valve opening cam or roller may be worn1 though this is not likely unless the roller or cam has been inadvertently left soft4 ,the pin which acts as a bearing for the roller may become worn1 this occurring quite often4 ,looseness may materialize between the bearing surfaces of the valve lift plunger and the plunger guide casting1 and there may also be excessive clearance between the top of the plunger and the valve stem4 ,illustration3 ,fig4 #ahe4--,outlining ,points in ,valve ,operating ,mechanism ,where ,depreciation is ,apt to ,exist4 ,on the form shown at ,a1 there are several parts added to those indicated at ,b4 ,a walking beam or rocker lever is necessary to transform the upward motion of the tappet rod to a downward motion of the valve stem4 ,the pin on which this member fulcrums may wear as will also the other pin acting as a hinge or bearing for the yoke end of the tappet rod4 ,it will be apparent that if slight play existed at each of the points mentioned it might result in a serious diminution of valve opening4 ,suppose1 for example1 that there were 4#jje-;inch lost motion at each of three bearing points1 the total lost motion would be 4#jae-;inch or sufficient to produce noisy action of the valve mechanism4 ,when valve plungers of the adjustable form1 such as shown at ,b1 are used1 the hardened bolt head in contact with the end of the valve stem may become hollowed out on account of the hammering action at that point4 ,it is imperative that the top of this member be ground off true and the clearance between the valve stem and plunger properly adjusted4 ,if the plunger is a non-adjustable type it will be necessary to lengthen the valve stem by some means in order to reduce the excessive clearance4 ,the only remedy for wear at the various hinges and bearing pins is to bore the holes out slightly larger and to fit new hardened steel pins of larger diameter4 ,depreciation between the valve plunger guide and the valve plunger is usually remedied by fitting new plunger guides in place of the worn ones4 ,if there is sufficient stock in the plunger guide casting as is sometimes the case when these members are not separable from the cylinder casting1 the guide may be bored out and bushed with a light bronze bushing4 ,a common cause of irregular engine operation is due to a sticking valve4 ,this may be owing to a bent valve stem1 a weak or broken valve spring or an accumulation of burnt or gummed oil between the valve stem and the valve stem guide4 ,in order to prevent this the valve stem must be smoothed with fine emery cloth and no burrs or shoulders allowed to remain on it1 and the stem must also be straight and at right angles to the valve head4 ,if the spring is weak it may be strengthened in some cases by stretching it out after annealing so that a larger space will exist between the coils and re-hardening4 ,obviously if a spring is broken the only remedy is replacement of the defective member4 ,mention has been made of wear in the valve stem guide and its influence on engine action4 ,when these members are an integral part of the cylinder the only method of compensating for this wear is to drill the guide out and fit a bushing1 which may be made of steel tube4 ,in some engines1 especially those of recent development1 the valve stem guide is driven or screwed into the cylinder casting and is a separate member which may be removed when worn and replaced with a new one4 ,when the guides become enlarged to such a point that considerable play exists between them and the valve stems1 they may be easily knocked out or unscrewed4 ,,piston ,,troubles ,if an engine has been entirely dismantled it is very easy to examine the pistons for deterioration4 ,while it is important that the piston be a good fit in the cylinder it is mainly upon the piston rings that compression depends4 ,the piston should fit the cylinder with but little looseness1 the usual practice being to have the piston about 4#jja-;inch smaller than the bore for each inch of piston diameter at the point where the least heat is present or at the bottom of the piston4 ,it is necessary to allow more than this at the top of the piston owing to its expansion due to the direct heat of the explosion4 ,the clearance is usually graduated and a piston that would be 4#jje-;inch smaller than the cylinder bore at the bottom would be about 4#jjfe-;inch at the middle and 4#jjge-;inch at the top4 ,if much more play than this is evidenced the piston will slap in the cylinder and the piston will be worn at the ends more than in the center4 ,aluminum or alloy pistons require more clearance than cast iron ones do1 usually #a4ej times as much4 ,pistons sometimes warp out of shape and are not truly cylindrical4 ,this results in the high spots rubbing on the cylinder while the low spots will be blackened where a certain amount of gas has leaked by4 ,mention has been previously made of the necessity of reboring or regrinding a cylinder that has become scored or scratched and which allows the gas to leak by the piston rings4 ,when the cylinder is ground out1 it is necessary to use a larger piston to conform to the enlarged cylinder bore4 ,most manufacturers are prepared to furnish over-size pistons1 there being four standard over-size dimensions adopted by the ,s4 ,a4 ,e4 for rebored cylinders4 ,these are 4#jaj-;inch1 4#jbj-;inch1 4#jcj-;inch1 and 4#jdj-;inch larger than the original bore4 ,the piston rings should be taken out of the piston grooves and all carbon deposits removed from the inside of the ring and the bottom of the groove4 ,it is important to take this deposit out because it prevents the rings from performing their proper functions by reducing the ring elasticity1 and if the deposit is allowed to accumulate it may eventually result in sticking and binding of the ring1 this producing excessive friction or loss of compression4 ,when the rings are removed they should be tested to see if they retain their elasticity and it is also well to see that the small pins in some pistons which keep the rings from turning around so the joints will not come in line are still in place4 ,if no pins are found there is no cause for alarm because these dowels are not always used4 ,when fitted1 they are utilized with rings having a butt joint or diagonal cut as the superior gas retaining qualities of the lap or step joint render the pins unnecessary4 ,if gas has been blowing by the ring or if these members have not been fitting the cylinder properly the points where the gas passed will be evidenced by burnt1 brown or roughened portions of the polished surface of the pistons and rings4 ,the point where this discoloration will be noticed more often is at the thin end of an eccentric ring1 the discoloration being present for about #a_/b-;inch or #c_/d-;inch each side of the slot4 ,it may be possible that the rings were not true when first put in4 ,this made it possible for the gas to leak by in small amounts initially which increased due to continued pressure until quite a large area for gas escape had been created4 ,,piston ,,ring ,,manipulation ,removing piston rings without breaking them is a difficult operation if the proper means are not taken1 but is a comparatively simple one when the trick is known4 ,the tools required are very simple1 being three strips of thin steel about one-quarter inch wide and four or five inches long and a pair of spreading tongs made up of one-quarter inch diameter keystock tied in the center with a copper wire to form a hinge4 ,the construction is such that when the hand is closed and the handles brought together the other end of the expander spreads out1 an action just opposite to that of the conventional pliers4 ,the method of using the tongs and the metal strips is clearly indicated at ,fig4 #ahf4 ,at ,a the ring expander is shown spreading the ends of the rings sufficiently to insert the pieces of sheet metal between one of the rings and the piston4 ,grasp the ring as shown at ,b1 pressing with the thumbs on the top of the piston and the ring will slide off easily1 the thin metal strips acting as guide members to prevent the ring from catching in the other piston grooves4 ,usually no difficulty is experienced in removing the top or bottom rings1 as these members may be easily expanded and worked off directly without the use of a metal strip4 ,when removing the intermediate rings1 however1 the metal strips will be found very useful4 ,these are usually made by the repairman by grinding the teeth from old hacksaw blades and rounding the edges and corners in order to reduce the liability of cutting the fingers4 ,by the use of the three metal strips a ring is removed without breaking or distorting it and practically no time is consumed in the operation4 ,,fitting ,,piston ,,rings ,before installing new rings1 they should be carefully fitted to the grooves to which they are applied4 ,the tools required are a large piece of fine emery cloth1 a thin1 flat file1 a small vise with copper or leaden jaw clips1 and a smooth hard surface such as that afforded by the top of a surface plate or a well planed piece of hard wood4 ,after making sure that all deposits of burnt oil and carbon have been removed from the piston grooves1 three rings are selected1 one for each groove4 ,the ring is turned all around its circumference into the groove it is to fit1 which can be done without springing it over the piston as the outside edge of the ring may be used to test the width of the groove just as well as the inside edge4 ,the ring should be a fair fit and while free to move circumferentially there should be no appreciable up and down motion4 ,if the ring is a tight fit it should be laid edge down upon the piece of emery cloth which is placed on the surface plate and carefully rubbed down until it fits the groove it is to occupy4 ,it is advisable to fit each piston ring individually and to mark them in some way to insure that they will be placed in the groove to which they are fitted4 ,the repairman next turns his attention to fitting the ring in the cylinder itself4 ,the ring should be pushed into the cylinder at least two inches up from the bottom and endeavor should be made to have the lower edge of the ring parallel with the bottom of the cylinder4 ,if the ring is not of correct diameter1 but is slightly larger than the cylinder bore1 this condition will be evident by the angular slots of the rings being out of line or by difficulty in inserting the ring if it is a lap joint form4 ,if such is the case the ring is removed from the cylinder and placed in the vise between soft metal jaw clips4 ,sufficient metal is removed with a fine file from the edges of the ring at the slot until the edges come into line and a slight space exists between them when the ring is placed into the cylinder4 ,it is important that this space be left between the ends1 for if this is not done when the ring becomes heated the expansion of metal may cause the ends to abut and the ring to jam in the cylinder4 ,illustration3 ,fig4 #ahf4--,method of ,removing ,piston ,rings1 and ,simple ,clamp to ,facilitate ,insertion of ,rings in ,cylinder4 ,it is necessary to use more than ordinary caution in replacing the rings on the piston because they are usually made of cast iron1 a metal that is very fragile and liable to break because of its brittleness4 ,special care should be taken in replacing new rings as these members are more apt to break than old ones4 ,this is probably accounted for by the heating action on used rings which tends to anneal the metal as well as making it less springy4 ,the bottom ring should be placed in position first which is easily accomplished by springing the ring open enough to pass on the piston and then sliding it into place in the lower groove which on some types of engines is below the wrist pin1 whereas in others all grooves are above that member4 ,the other members are put in by a reversal of the process outlined at ,fig4 #ahf1 ,a and ,b4 ,it is not always necessary to use the guiding strips of metal when replacing rings as it is often possible1 by putting the rings on the piston a little askew and maneuvering them to pass the grooves without springing the ring into them4 ,the top ring should be the last one placed in position4 ,before placing pistons in the cylinder one should make sure that the slots in the piston rings are spaced equidistant on the piston1 and if pins are used to keep the ring from turning one should be careful to make sure that these pins fit into their holes in the ring and that they are not under the ring at any point4 ,practically all cylinders are chamfered at the lower end to make insertion of piston rings easier4 ,the operation of putting on a cylinder casting over a piston really requires two pairs of hands1 one to manipulate the cylinder1 the other person to close the rings as they enter the cylinder4 ,this may be done very easily by a simple clamp member made of sheet brass or iron and used to close the ring as indicated at ,fig4 #ahf1 ,c4 ,it is apparent that the clamp must be adjusted to each individual ring and that the split portion of the clamp must coincide with the split portion of the ring4 ,the cylinder should be well oiled before any attempt is made to install the pistons4 ,the engine should be run with more than the ordinary amount of lubricant for several hours after new piston rings have been inserted4 ,on first starting the engine1 one may be disappointed in that the compression is even less than that obtained with the old rings4 ,this condition will soon be remedied as the rings become polished and adapt themselves to the contour of the cylinder4 ,,wrist ,,pin ,,wear ,while wrist pins are usually made of very tough steel1 case hardened with the object of wearing out an easily renewable bronze bushing in the upper end of the connecting rod rather than the wrist pin it sometimes happens that these members will be worn so that even the replacement of a new bushing in the connecting rod will not reduce the lost motion and attendant noise due to a loose wrist pin4 ,the only remedy is to fit new wrist pins to the piston4 ,where the connecting rod is clamped to the wrist pin and that member oscillates in the piston bosses the wear will usually be indicated on bronze bushings which are pressed into the piston bosses4 ,these are easily renewed and after running a reamer through them of the proper size no difficulty should be experienced in replacing either the old or a new wrist pin depending upon the condition of that member4 ,if no bushings are provided1 as in alloy pistons1 the bosses can sometimes be bored out and thin bushings inserted1 though this is not always possible4 ,the alternative is to ream out the bosses and upper end of rod a trifle larger after holes are trued up and fit oversize wrist pins4 ,,inspection ,,and ,,refitting ,,of ,,engine ,,bearings ,while the engine is dismantled one has an excellent opportunity to examine the various bearing points in the engine crank-case to ascertain if any looseness exists due to depreciation of the bearing surfaces4 ,as will be evident1 both main crank-shaft bearings and the lower end of the connecting rods may be easily examined for deterioration4 ,with the rods in place1 it is not difficult to feel the amount of lost motion by grasping the connecting rod firmly with the hand and moving it up and down4 ,after the connecting rods have been removed and the propeller hub taken off the crank-shaft to permit of ready handling1 any looseness in the main bearing may be detected by lifting up on either the front or rear end of the crank-shaft and observing if there is any lost motion between the shaft journal and the main bearing caps4 ,it is not necessary to take an engine entirely apart to examine the main bearings1 as in most forms these may be readily reached by removing the sump4 ,the symptoms of worn main bearings are not hard to identify4 ,if an engine knocks regardless of speed or spark-lever position1 and the trouble is not due to carbon deposits in the combustion chamber1 one may reasonably surmise that the main bearings have become loose or that lost motion may exist at the connecting rod big ends1 and possibly at the wrist pins4 ,the main journals of any well resigned engine are usually proportioned with ample surface and will not wear unduly unless lubrication has been neglected4 ,the connecting rod bearings wear quicker than the main bearings owing to being subjected to a greater unit stress1 and it may be necessary to take these up4 ,,adjusting ,,main ,,bearings ,illustration3 ,fig4 #ahg4--,tools and ,processes ,used in ,refitting ,engine ,bearings4 ,when the bearings are not worn enough to require refitting the lost motion can often be eliminated by removing one or more of the thin shims or liners ordinarily used to separate the bearing caps from the seat4 ,these are shown at ,fig4 #ahg1 ,a4 ,care must be taken that an even number of shims of the same thickness are removed from each side of the journal4 ,if there is considerable lost motion after one or two shims have been removed1 it will be advisable to take out more shims and to scrape the bearing to a fit before the bearing cap is tightened up4 ,it may be necessary to clean up the crank-shaft journals as these may be scored due to not having received clean oil or having had bearings seize upon them4 ,it is not difficult to true up the crank-pins or main journals if the score marks are not deep4 ,a fine file and emery cloth may be used1 or a lapping tool such as depicted at ,fig4 #ahg1 ,b4 ,the latter is preferable because the file and emery cloth will only tend to smooth the surface while the lap will have the effect of restoring the crank to proper contour4 ,a lapping tool may be easily made1 as shown at ,b1 the blocks being of lead or hard wood4 ,as the width of these are about half that of the crank-pin the tool may be worked from side to side as it is rotated4 ,an abrasive paste composed of fine emery powder and oil is placed between the blocks1 and the blocks are firmly clamped to the crank-pin4 ,as the lead blocks bed down1 the wing nut should be tightened to insure that the abrasive will be held with some degree of pressure against the shaft4 ,a liberal supply of new abrading material is placed between the lapping blocks and crank-shaft from time to time and the old mixture cleaned off with gasoline4 ,it is necessary to maintain a side to side movement of the lapping tool in order to have the process affect the whole width of the crank-pin equally4 ,the lapping is continued until a smooth surface is obtained4 ,if a crank-pin is worn out of true to any extent the only method of restoring it is to have it ground down to proper circular form by a competent mechanic having the necessary machine tools to carry on the work accurately4 ,a crank-pin truing tool that may be worked by hand is shown at ,fig4 #ahg1 ,k4 ,after the crank-shaft is trued the next operation is to fit it to the main bearings or rather to scrape these members to fit the shaft journal4 ,in order to bring the brasses closer together1 it may be necessary to remove a little metal from the edges of the caps to compensate for the lost motion4 ,a very simple way of doing this is shown at ,fig4 #ahg1 ,d4 ,a piece of medium emery cloth is rested on the surface plate and the box or brass is pushed back and forth over that member by hand1 the amount of pressure and rapidity of movement being determined by the amount of metal it is necessary to remove4 ,this is better than filing1 because the edges will be flat and there will be no tendency for the bearing caps to rock when placed against the bearing seat4 ,it is important to take enough off the edges of the boxes to insure that they will grip the crank tightly4 ,the outer diameter must be checked with a pair of calipers during this operation to make sure that the surfaces remain parallel4 ,otherwise1 the bearing brasses will only grip at one end and with such insufficient support they will quickly work loose1 both in the bearing seat and bearing cap4 ,,scraping ,,brasses ,,to ,,fit ,to insure that the bearing brasses will be a good fit on the trued-up crank-pins or crank-shaft journals1 they must be scraped to fit the various crank-shaft journals4 ,the process of scraping1 while a tedious one1 is not difficult1 requiring only patience and some degree of care to do a good job4 ,the surface of the crank-pin is smeared with ,prussian blue pigment which is spread evenly over the entire surface4 ,the bearings are then clamped together in the usual manner with the proper bolts1 and the crank-shaft revolved several times to indicate the high spots on the bearing cap4 ,at the start of the process of scraping in1 the bearing may seat only at a few points as shown at ,fig4 #ahg1 ,g4 ,continued scraping will bring the bearing surface as indicated at ,h1 which is a considerable improvement1 while the process may be considered complete when the brass indicates a bearing all over as at ,i4 ,the high spots are indicated by blue1 as where the shaft does not bear on the bearing there is no color4 ,the high spots are removed by means of a scraping tool of the form shown at ,fig4 #ahg1 ,f1 which is easily made from a worn-out file4 ,these are forged to shape and ground hollow as indicated in the section1 and are kept properly sharpened by frequent rubbing on an ordinary oil stone4 ,to scrape properly1 the edge of the scraper must be very keen4 ,the straight and curved half-round scrapers1 shown at ,m and ,n1 are used for bearings4 ,the three-cornered scraper1 outlined at ,o1 is also used on curved surfaces1 and is of value in rounding off the sharp corners4 ,the straight or curved half-round type works well on soft-bearing metals1 such as babbitt1 or white brass1 but on yellow brass or bronze it cuts very slowly1 and as soon as the edge becomes dull considerable pressure is needed to remove any metal1 this calling for frequent sharpening4 ,when correcting errors on flat or curved surfaces by hand-scraping1 it is desirable1 of course1 to obtain an evenly spotted bearing with as little scraping as possible4 ,when the part to be scraped is first applied to the surface-plate1 or to a journal in the case of a bearing1 three or four high spots may be indicated by the marking material4 ,the time required to reduce these high spots and obtain a bearing that is distributed over the entire surface depends largely upon the way the scraping is started4 ,if the first bearing marks indicate a decided rise in the surface1 much time can be saved by scraping larger areas than are covered by the bearing marks2 this is especially true of large shaft and engine bearings1 etc4 ,an experienced workman will not only remove the heavy marks1 but also reduce a larger area2 then1 when the bearing is tested again1 the marks will generally be distributed somewhat4 ,if the heavy marks which usually appear at first are simply removed by light scraping1 these point bearings are gradually enlarged1 but a much longer time will be required to distribute them4 ,the number of times the bearing must be applied to the journal for testing is important1 especially when the box or bearing is large and not easily handled4 ,the time required to distribute the bearing marks evenly depends largely upon one's judgment in reading these marks4 ,in the early stages of the scraping operation1 the marks should be used partly as a guide for showing the high areas1 and instead of merely scraping the marked spot the surface surrounding it should also be reduced1 unless it is evident that the unevenness is local4 ,the idea should be to obtain first a few large but generally distributed marks2 then an evenly and finely spotted surface can be produced quite easily4 ,in fitting brasses when these are of the removable type1 two methods may be used4 ,the upper half of the engine base may be inverted on a suitable bench or stand and the boxes fitted by placing the crank-shaft in position1 clamping down one bearing cap at a time and fitting each bearing in succession until they bed equally4 ,from that time on the bearings should be fitted at the same time so the shaft will be parallel with the bottom of the cylinders4 ,considerable time and handling of the heavy crank-shaft may be saved if a preliminary fitting of the bearing brasses is made by clamping them together with a carpenter's wood clamp as shown at ,fig4 #ahg1 ,j1 and leaving the crank-shaft attached to the bench as shown at ,c4 ,the brasses are revolved around the crank-shaft journal and are scraped to fit wherever high spots are indicated until they begin to seat fairly4 ,when the brasses assume a finished appearance the final scraping should be carried on with all bearings in place and revolving the crank-shaft to determine the area of the seating4 ,when the brasses are properly fitted they will not only show a full bearing surface1 but the shaft will not turn unduly hard if revolved with a moderate amount of leverage4 ,bearings of white metal or babbitt can be fitted tighter than those of bronze1 and care must be observed in supplying lubricant as considerably more than the usual amount is needed until the bearings are run in by several hours of test block work4 ,before the scraping process is started it is well to chisel an oil groove in the bearing as shown at ,fig4 #ahg1 ,l4 ,grooves are very helpful in insuring uniform distribution of oil over the entire width of bearing and at the same time act as reservoirs to retain a supply of oil4 ,the tool used is a round-nosed chisel1 the effort being made to cut the grooves of uniform depth and having smooth sides4 ,care should be taken not to cut the grooves too deeply1 as this will seriously reduce the strength of the bearing bushing4 ,the shape of the groove ordinarily provided is clearly shown at ,fig4 #ahg1 ,g1 and it will be observed that the grooves do not extend clear to the edge of the bearing1 but stop about a quarter of an inch from that point4 ,the hole through which the oil is supplied to the bearing is usually drilled in such a way that it will communicate with the groove4 ,the tool shown at ,fig4 #ahg1 ,k1 is of recent development1 and is known as a crank-shaft equalizer4 ,this is a hand-operated turning tool1 carrying cutters which are intended to smooth down scored crank-pins without using a lathe4 ,the feed may be adjusted by suitable screws and the device may be fitted to crank-pins and shaft-journals of different diameters by other adjusting screws4 ,this device is not hard to operate1 being merely clamped around the crank-shaft in the same manner as the lapping tool previously described1 and after it has been properly adjusted it is turned around by the levers provided for the purpose1 the continuous rotary motion removing the metal just as a lathe tool would4 ,,fitting ,,connecting ,,rods ,in the marine type rod1 which is the form generally used in airplane engines1 one or two bolts are employed at each side and the cap must be removed entirely before the bearing can be taken off of the crank-pin4 ,the tightness of the brasses around the crank-pin can never be determined solely by the adjustment of the bolts1 as while it is important that these should be drawn up as tightly as possible1 the bearing should fit the shaft without undue binding1 even if the brasses must be scraped to insure a proper fit4 ,as is true of the main bearings1 the marine form of connecting rod in some engines has a number of liners or shims interposed between the top and lower portions of the rod end1 and these may be reduced in number when necessary to bring the brasses closer together4 ,the general tendency in airplane engines is to eliminate shims in either the main or connecting rod bearings1 and when wear is noticed the boxes or liners are removed and new ones supplied4 ,the brasses are held in the connecting rod and cap by brass rivets and are generally attached in the main bearing by small brass machine screws4 ,the form of box generally favored is a brass sand casting rich in copper to secure good heat conductivity which forms a backing for a thin layer of white brass1 babbitt or similar anti-friction metal4 ,illustration3 ,fig4 #ahh4--,showing ,points to ,observe ,when ,fitting ,connecting ,rod ,brasses4 ,in fitting new brasses there are two conditions to be avoided1 these being outlined at ,fig4 #ahh1 ,b and ,c4 ,in the case shown at ,c the light edges of the bushings are in contact1 but the connecting rod and its cap do not meet4 ,when the retaining nuts are tightened the entire strain is taken on the comparatively small area of the edges of the bushings which are not strong enough to withstand the strains existing and which flatten out quickly1 permitting the bearing to run loose4 ,in the example outlined at ,b the edges of the brasses do not touch when the connecting rod cap is drawn in place4 ,this is not good practice1 because the brasses soon become loose in their retaining member4 ,in the case outlined it is necessary to file off the faces of the rod and cap until these meet1 and to insure contact of the edges of the brasses as well4 ,in event of the brasses coming together before the cap and rod make contact1 as shown at ,c1 the bearing halves should be reduced at the edges until both the caps and brasses meet against each other or the surfaces of the liners as shown at ,a4 ,,sprung ,,cam-,,shaft ,if the cam-shaft is sprung or twisted it will alter the valve timing to such an extent that the smoothness of operation of the engine will be materially affected4 ,if this condition is suspected the cam-shaft may be swung on lathe centers and turned to see if it runs out and can be straightened in any of the usual form of shaft-straightening machines4 ,the shaft may be twisted without being sprung4 ,this can only be determined by supporting one end of the shaft in an index head and the other end on a milling machine center4 ,the cams are then checked to see that they are separated by the proper degree of angularity4 ,this process is one that requires a thorough knowledge of the valve timing of the engine in question1 and is best done at the factory where the engine was made4 ,the timing gears should also be examined to see if the teeth are worn enough so that considerable back lash or lost motion exists between them4 ,this is especially important where worm or spiral gears are used4 ,a worn timing gear not only produces noise1 but it will cause the time of opening and closing of the engine valves to vary materially4 ,,precautions ,,in ,,reassembling ,,parts ,when all of the essential components of a power plant have been carefully looked over and cleaned and all defects eliminated1 either by adjustment or replacement of worn portions1 the motor should be reassembled1 taking care to have the parts occupy just the same relative positions they did before the motor was dismantled4 ,as each part is added to the assemblage care should be taken to insure adequate lubrication of all new points of bearing by squirting liberal quantities of cylinder oil upon them with a hand oil can or syringe provided for the purpose4 ,in adjusting the crank-shaft bearings1 tighten them one at a time and revolve the shafts each time one of the bearing caps is set up to insure that the newly adjusted bearing does not have undue friction4 ,all retaining keys and pins must be positively placed and it is good practice to cover such a part with lubricant before replacing it because it will not only drive in easier1 but the part may be removed more easily if necessary at some future time4 ,if not oiled1 rust collects around it4 ,when a piece is held by more than one bolt or screw1 especially if it is a casting of brittle material such as cast iron or aluminum1 the fastening bolts should be tightened uniformly4 ,if one bolt is tightened more than the rest it is liable to spring the casting enough to break it4 ,spring washers1 check nuts1 split pins or other locking means should always be provided1 especially on parts which are in motion or subjected to heavy loads4 ,before placing the cylinder over the piston it is imperative that the slots in the piston rings are spaced equidistant and that the piston is copiously oiled before the cylinder is slipped over it4 ,when reassembling the inlet and exhaust manifolds it is well to use only perfect packings or gaskets and to avoid the use of those that seem to have hardened up or flattened out too much in service4 ,if it is necessary to use new gaskets it is imperative to employ these at all joints on a manifold1 because if old and new gaskets are used together the new ones are apt to keep the manifold from bedding properly upon the used ones4 ,it is well to coat the threads of all bolts and screws subjected to heat1 such as cylinder head and exhaust manifold retaining bolts1 with a mixture of graphite and oil4 ,those that enter the water jacket should be covered with white or red lead or pipe thread compound4 ,gaskets will hold better if coated with shellac before the manifold or other parts are placed over them4 ,the shellac fills any irregularities in the joint and assists materially in preventing leakage after the joint is made up and the coating has a chance to set4 ,before assembling on the shaft1 it is necessary to fit the bearings by scraping1 the same instructions given for restoring the contour of the main bearings applying just as well in this case4 ,it is apparent that if the crank-pins are not round no amount of scraping will insure a true bearing4 ,a point to observe is to make sure that the heads of the bolts are imbedded solidly in their proper position1 and that they are not raised by any burrs or particles of dirt under the head which will flatten out after the engine has been run for a time and allow the bolts to slack off4 ,similarly1 care should be taken that there is no foreign matter under the brasses and the box in which they seat4 ,to guard against this the bolts should be struck with a hammer several times after they are tightened up1 and the connecting rod can be hit sharply several times under the cap with a wooden mallet or lead hammer4 ,it is important to pin the brasses in place to prevent movement1 as lubrication may be interfered with if the bushing turns round and breaks the correct register between the oil hole in the cap and brasses4 ,care should be taken in screwing on the retaining nuts to insure that they will remain in place and not slack off4 ,spring washers should not be used on either connecting rod ends or main bearing nuts1 because these sometimes snap in two pieces and leave the nut slack4 ,the best method of locking is to use well-fitting split pins and castellated nuts4 ,,testing ,,bearing ,,parallelism ,it is not possible to give other than general directions regarding the proper degree of tightening for a connecting rod bearing1 but as a guide to correct adjustment it may be said that if the connecting rod cap is tightened sufficiently so the connecting rod will just about fall over from a vertical position due to the piston weight when the bolts are fully tightened up1 the adjustment will be nearly correct4 ,as previously stated1 babbitt or white metal bearings can be set up more tightly than bronze1 as the metal is softer and any high spots will soon be leveled down with the running of the engine4 ,it is important that care be taken to preserve parallelism of the wrist-pins and crank-shafts while scraping in bearings4 ,this can be determined in two ways4 ,that shown at ,fig4 #ahi1 ,a1 is used when the parts are not in the engine assembly and when the connecting rod bearing is being fitted to a mandrel or arbor the same size as the crank-pin4 ,the arbor1 which is finished very smooth and of uniform diameter1 is placed in two ,v blocks1 which in turn are supported by a level surface plate4 ,an adjustable height gauge may be tried1 first at one side of the wrist-pin which is placed at the upper end of the connecting rod1 then at the other1 and any variation will be easily determined by the degree of tilting of the rod4 ,this test may be made with the wrist-pin alone1 or if the piston is in place1 a straight edge or spirit level may be employed4 ,the spirit level will readily show any inclination while the straight edge is used in connection with the height gauge as indicated4 ,of course1 the surface plate must be absolutely level when tests are made4 ,when the connecting rods are being fitted with the crank-shaft in place in crank-case1 and that member secured in the frame1 a steel square may be used as it is reasonable to assume that the wrist-pin1 and consequently the piston it carries1 should observe a true relation with the top of the engine base4 ,if the piston side is at right angles with the top of the engine base it is reasonable to assume that the wrist-pin and crank-pin are parallel4 ,if the piston is canted to one side or the other1 it will indicate that the brasses have been scraped tapering1 which would mean considerable heating and undue friction if the piston is installed in the cylinder on account of the pressure against one portion of the cylinder wall4 ,if the degree of canting is not too great1 the connecting rods may be sprung very slightly to straighten up the piston1 but this is a makeshift that is not advised4 ,the height gauge method shown above may be used instead of the steel square1 if desired1 because the top of the crank-case is planed or milled true and should be parallel with the center line of the crank-shaft4 ,illustration3 ,fig4 #ahi4--,methods of ,testing to ,insure ,parallelism of ,bearings ,after ,fitting4 ,,cam-,,shafts ,,and ,,timing ,,gears ,knocking sounds are also evident if the cam-shaft is loose in its bearings1 and also if the cams or timing gears are loose on the shaft4 ,the cam-shaft is usually supported by solid bearings of the removable bushing type1 having no compensation for depreciation4 ,if these bearings wear the only remedy is replacement with new ones4 ,in the older makes of cars it was general practice to machine the cams separately and to secure these to the cam-shaft by means of taper pins or keys4 ,these members sometimes loosened and caused noise4 ,in the event of the cams being loose1 care should be taken to use new keys or taper pins1 as the case may be4 ,if the fastening used was a pin1 the hole through the cam-shaft will invariably be slightly oval from wear4 ,in order to insure a tight job1 the holes in cam and shaft must be reamed with the next larger size of standard taper reamer and a larger pin driven in4 ,another point to watch is the method of retaining the cam-shaft gear in place4 ,on some engines the gear is fastened to a flange on the cam-shaft by retaining screws4 ,these are not apt to become loose1 but where reliance is placed on a key the cam-shaft gear may often be loose on its supporting member4 ,the only remedy is to enlarge the key slot in both gear and shaft and to fit a larger retaining key4 ,,chapter ,,xii ,aviation ,engine ,types--,division in ,classes--,anzani ,engines-- ,canton and ,unne ,engine--,construction of ,gnome ,engines-- ,monosoupape ,gnome--,german ,gnome ,type--,le ,rhone ,engine-- ,renault ,air-,cooled ,engine--,simplex ,model ,a ,hispano-,suiza-- ,curtiss ,aviation ,motors--,thomas-,morse ,model #hh ,engine-- ,duesenberg ,engine--,aeromarine ,six-,cylinder--,wisconsin ,aviation ,engines--,hall-,scott ,engines--,mercedes ,motor--,benz ,motor-- ,austro-,daimler--,sunbeam-,coatalen4 ,,aviation ,,engine ,,types ,inasmuch as numerous forms of airplane engines have been devised1 it would require a volume of considerable size to describe even the most important developments of recent years4 ,as considerable explanatory matter has been given in preceding chapters and the principles involved in internal combustion engine operation considered in detail1 a relatively brief review of the features of some of the most successful airplane motors should suffice to give the reader a complete enough understanding of the art so all types of engines can be readily recognized and the advantages and disadvantages of each type understood1 as well as defining the constructional features enough so the methods of locating and repairing the common engine and auxiliary system troubles will be fully grasped4 ,aviation engines can be divided into three main classes4 ,one of the earliest attempts to devise distinctive power plant designs for aircraft involved the construction of engines utilizing a radial arrangement of the cylinders or a star-wise disposition4 ,among the engines of this class may be mentioned the ,anzani1 ,r4 ,e4 ,p4 and the ,salmson or ,canton and ,unne forms4 ,the two former are air-cooled1 the latter design is water-cooled4 ,engines of this type have been built in cylinder numbers ranging from three to twenty4 ,while the simple forms were popular in the early days of aviation engine development1 they have been succeeded by the more conventional arrangements which now form the largest class4 ,the reason for the adoption of a star-wise arrangement of cylinders has been previously considered4 ,smoothness of running can only be obtained by using a considerable number of cylinders4 ,the fundamental reason for the adoption of the star-wise disposition is that a better distribution of stress is obtained by having all of the pistons acting on the same crank-pin so that the crank-throw and pin are continuously under maximum stress4 ,some difficulty has been experienced in lubricating the lower cylinders in some forms of six cylinder1 rotary crank1 radial engines but these have been largely overcome so they are not as serious in practice as a theoretical consideration would indicate4 ,another class of engines developed to meet aviation requirements is a complete departure from the preceding class1 though when the engines are at rest1 it is difficult to differentiate between them4 ,this class includes engines having a star-wise disposition of the cylinders but the cylinders themselves and the crank-case rotate and the crank-shaft remains stationary4 ,the important rotary engines are the ,gnome1 the ,le ,rhone and the ,clerget4 ,by far the most important classification is that including engines which retain the approved design of the types of power plants that have been so widely utilized in automobiles and which have but slight modifications to increase reliability and mechanical strength and produce a reduction in weight4 ,this class includes the vertical engines such as the ,duesenberg and ,hall-,scott four-cylinder2 the ,wisconsin1 ,aeromarine1 ,mercedes1 ,benz1 and ,hall-,scott six-cylinder vertical engines and the numerous eight- and twelve-cylinder ,vee designs such as the ,curtiss1 ,renault1 ,thomas-,morse1 ,sturtevant1 ,sunbeam1 and others4 ,,anzani ,,engines ,the attention of the mechanical world was first directed to the great possibilities of mechanical flight when ,bleriot crossed the ,english ,channel in ,july1 #aiji1 in a monoplane of his own design and construction1 having the power furnished by a small three-cylinder air-cooled engine rated at about #bd horse-power and having cylinders #d4ac inches bore and #e4ab inches stroke1 stated to develop the power at about #afjj ,r4,p4,m4 and weighing #ade pounds4 ,the arrangement of this early ,anzani engine is shown at ,fig4 #aij1 and it will be apparent that in the main1 the lines worked out in motorcycle practice were followed to a large extent4 ,the crank-case was of the usual vertically divided pattern1 the cylinders and heads being cast in one piece and held to the crank-case by stud bolts passing through substantial flanges at the cylinder base4 ,in order to utilize but a single crank-pin for the three cylinders it was necessary to use two forked rods and one rod of the conventional type4 ,the arrangement shown at ,fig4 #aij1 called for the use of counter-balanced flywheels which were built up in connection with shafts and a crank-pin to form what corresponds to the usual crank-shaft assembly4 ,illustration3 ,fig4 #aij4--,views ,outlining ,construction of ,three-,cylinder ,anzani ,aviation ,motor4 ,the inlet valves were of the automatic type so that a very simple valve mechanism consisting only of the exhaust valve push rods was provided4 ,one of the difficulties of this arrangement of cylinders was that the impulses are not evenly spaced4 ,for instance1 in the forms where the cylinders were placed #fj degrees apart the space between the firing of the first cylinder and that next in order was #abj degrees crank-shaft rotation1 after which there was an interval of #cjj degrees before the last cylinder to fire delivered its power stroke4 ,in order to increase the power given by the simple three-cylinder air-cooled engine a six-cylinder water-cooled type1 as shown at ,figs4 #aia and #aib1 was devised4 ,this was practically the same in action as the three-cylinder except that a double throw crank-shaft was used and while the explosions were not evenly spaced the number of explosions obtained resulted in fairly uniform application of power4 ,illustration3 ,fig4 #aij;a4--,illustrations ,depicting ,wrong and ,right ,methods of ,swinging the ,stick to ,start ,airplane ,engine4 ,at ,top1 ,poor ,position to ,get ,full ,throw and ,get ,out of the ,way4 ,below1 ,correct ,position to ,get ,quick ,turn ,over of ,crank-,shaft and ,spring ,away from ,propeller4 ,illustration3 ,fig4 #aia4--,the ,anzani ,six-,cylinder ,water-,cooled ,aviation ,engine4 ,illustration3 ,fig4 #aib4--,sectional ,view of ,anzani ,six-,cylinder ,water-,cooled ,aviation ,engine4 ,the latest design of three-cylinder ,anzani engine1 which is used to some extent for school machines1 is shown at ,fig4 #aic4 ,in this1 the three-cylinders are symmetrically arranged about the crank-case or #abj degrees apart4 ,the balance is greatly improved by this arrangement and the power strokes occur at equal intervals of #bdj degrees of crank-shaft rotation4 ,this method of construction is known as the ,y design4 ,by grouping two of these engines together1 as outlined at ,fig4 #aid1 which gives an internal view1 and at ,fig4 #aie1 which shows the sectional view1 and using the ordinary form of double throw crank-shaft with crank-pins separated by #ahj degrees1 a six-cylinder radial engine is produced which runs very quietly and furnishes a steady output of power4 ,the peculiarity of the construction of this engine is in the method of grouping the connecting rod about the common crank-pin without using forked rods or the ,mother rod system employed in the ,gnome engines4 ,in the ,anzani the method followed is to provide each connecting rod big end with a shoe which consists of a portion of a hollow cylinder held against the crank-pin by split clamping rings4 ,the dimensions of these shoes are so proportioned that the two adjacent connecting rods of a group of three will not come into contact even when the connecting rods are at the minimum relative angle4 ,the three shoes of each group rest upon a bronze sleeve which is in halves and which surrounds the crank-pin and rotates relatively to it once in each crank-shaft revolution4 ,the collars1 which are of tough bronze1 resist the inertia forces while the direct pressure of the explosions is transmitted directly to the crank-pin bushing by the shoes at the big end of the connecting rod4 ,the same method of construction1 modified to some extent1 is used in the ,le ,rhone rotary cylinder engine4 ,illustration3 ,fig4 #aic4--,three-,cylinder ,anzani ,air-,cooled ,y-,form ,engine4 ,illustration3 ,fig4 #aid4--;,anzani ,fixed ,crank-,case ,engine of the ,six-,cylinder ,form ,utilizes ,air ,cooling ,successfully4 ,both cylinders and pistons of the ,anzani engines are of cast iron1 the cylinders being provided with a liberal number of cooling flanges which are cast integrally4 ,a series of auxiliary exhaust ports is drilled near the base of each cylinder so that a portion of the exhaust gases will flow out of the cylinder when the piston reaches the end of its power stroke4 ,this reduces the temperature of the gases passing around the exhaust valves and prevents warping of these members4 ,another distinctive feature of this engine design is the method of attaching the ,zenith carburetor to an annular chamber surrounding the rear portion of the crank-case from which the intake pipes leading to the intake valves radiate4 ,the magneto is the usual six-cylinder form having the armature geared to revolve at one and one-half times crank-shaft speed4 ,illustration3 ,fig4 #aie4--,sectional ,view ,showing ,internal ,parts of ,six-,cylinder ,anzani ,engine1 with ,starwise ,disposition of ,cylinders4 ,illustration3 ,fig4 #aif4--,the ,anzani ,ten-,cylinder ,aviation ,engine at the ,left1 and the ,twenty-,cylinder ,fixed ,type at the ,right4 ,the ,anzani aviation engines are also made in ten- and twenty-cylinder forms as shown at ,fig4 #aif4 ,it will be apparent that in the ten-cylinder form explosions will occur every #gb degrees of crank-shaft rotation1 while in the twenty-cylinder1 #bjj horse-power engine at any instant five of the cylinders are always working and explosions are occurring every #cf degrees of crank-shaft rotation4 ,on the twenty-cylinder engine1 two carburetors are used and two magnetos1 which are driven at two and one-half times crank-shaft speed4 ,the general cylinder and valve construction is practically the same1 as in the simpler engines4 ,illustration3 ,fig4 #aig4--;,application of ,r4 ,e4 ,p4 ,five-,cylinder ,fan-,shape ,air-,cooled ,motor to ,early ,monoplane4 ,,canton ,,and ,,unne ,,engine ,this engine1 which has been devised specially for aviation service1 is generally known as the ,salmson and is manufactured in both ,france and ,great ,britain4 ,it is a nine-cylinder water-cooled radial engine1 the nine cylinders being symmetrically disposed around the crank-shaft while the nine connecting rods all operate on a common crank-pin in somewhat the same manner as the rods in the ,gnome motor4 ,the crank-shaft of the ,salmson engine is not a fixed one and inasmuch as the cylinders do not rotate about the crank-shaft it is necessary for that member to revolve as in the conventional engine4 ,the stout hollow steel crank-shaft is in two pieces and has a single throw4 ,the crank-shaft is built up somewhat the same as that of the ,gnome engine4 ,ball bearings are used throughout this engine as will be evident by inspecting the sectional view given at ,fig4 #aii4 ,the nine steel connecting rods are machined all over and are fitted at each end with bronze bushings1 the distance between the bearing centers being about #c4be times crank length4 ,the method of connecting up the rods to the crank-pin is one of the characteristic features of this design4 ,no mother rod as supplied in the ,gnome engine is used in this type inasmuch as the steel cage or connecting rod carrier is fitted with symmetrically disposed big end retaining pins4 ,inasmuch as the carrier is mounted on ball bearings some means must be provided of regulating the motion of the carrier as if no means were provided the resulting motion of the pistons would be irregular4 ,illustration3 ,fig4 #aih4--,the ,canton and ,unne ,nine-,cylinder ,water-,cooled ,radial ,engine4 ,the method by which the piston strokes are made to occur at precise intervals involves a somewhat lengthy and detailed technical explanation4 ,it is sufficient to say that an epicyclic train of gears1 one of which is rigidly attached to the crank-case so it cannot rotate is used1 while other gears make a connection between the fixed gear and with another gear which is exactly the same size as the fixed gear attached to the crank-case and which is formed integrally with the connecting rod carrier4 ,the action of the gearing is such that the cage carrying the big end retaining pins does not rotate independently of the crank-shaft1 though1 of course1 the crank-shaft or rather crank-pin bearings must turn inside of the big end carrier cage4 ,illustration3 ,fig4 #aii4--,sectional ,view ,showing ,construction of ,canton and ,unne ,water-,cooled ,radial ,cylinder ,engine4 ,cylinders of this engine are of nickel steel machined all over and carry water-jackets of spun copper which are attached to the cylinders by brazing4 ,the water jackets are corrugated to permit the cylinder to expand freely4 ,the ignition is similar to that of the fixed crank rotating cylinder engine4 ,an ordinary magneto of the two spark type driven at #a-c_/d times crank-shaft speed is sufficient to ignite the seven-cylinder form1 while in the nine-cylinder engines the ignition magneto is of the shield type giving four sparks per revolution4 ,the magneto is driven at #a-a_/i times crank-shaft speed4 ,nickel steel valves are used and are carried in castings or cages which screw into bosses in the cylinder head4 ,each valve is cam operated through a tappet1 push rod and rocker arm1 seven cams being used on a seven-cylinder engine and nine cams on the nine-cylinder4 ,one cam serves to open both valves as in its rotation it lifts the tappets in succession and so operates the exhaust and inlet valves respectively4 ,this method of operation involves the same period of intake and exhaust4 ,in normal engine practice the inlet valve opens #ab degrees late and closes #bj degrees late4 ,the exhaust opens #de degrees early and closes #f degrees late4 ,this means about #ahh degrees in the case of inlet valve and #bca degrees crank-shaft travel for exhaust valves4 ,in the ,salmson engine1 the exhaust closes and the inlet opens at the outer dead center and the exhaust opens and the inlet closes at about the inner dead center4 ,this engine is also made in a fourteen-cylinder #bjj ,b4 ,h4 ,p4 design which is composed of two groups of seven-cylinders1 and it has been made in an eighteen-cylinder design of #fjj horse-power4 ,the nine-cylinder #acj horse-power has a cylinder bore of #d4gc inches and a stroke of #e4eb inches4 ,its normal speed of rotation is #abej ,r4 ,p4 ,m4 ,owing to the radial arrangement of the cylinders1 the weight is but #d-a_/d pounds per ,b4 ,h4 ,p4 ,,construction ,,of ,,early ,,gnome ,,motor ,it cannot be denied that for a time one of the most widely used of aeroplane motors was the seven-cylinder revolving air-cooled ,gnome1 made in ,france4 ,for a total weight of #afg pounds this motor developed #de to #dg horse-power at #a1jjj revolutions1 being equal to #c4ce pounds per horse-power1 and has proved its reliability by securing many long-distance and endurance records4 ,the same engineers have produced a nine-cylinder and by combining two single engines a fourteen-cylinder revolving ,gnome1 having a nominal rating of #ajj horse-power1 with which world's speed records were broken4 ,a still more powerful engine has been made with eighteen-cylinders4 ,the nine-cylinder monosoupape delivers #ajj horse-power at #abjj ,r4 ,p4 ,m41 the engine of double that number of cylinders is rated at about #ahj horse-power4 ,illustration3 ,fig4 #bjj4--,sectional ,view ,outlining ,construction of ,early ,type ,gnome ,valve-in-,piston ,type ,motor4 ,except in the number of cylinders and a few mechanical details the fourteen-cylinder motor is identical with the seven-cylinder one2 fully three-quarters of the parts used by the assemblers would do just as well for one motor as for the other4 ,owing to the greater power demands of the modern airplane the smaller sizes of ,gnome engines are not used as much as they were except for school machines4 ,there is very little in this motor that is common to the standard type of vertical motorcar engine4 ,the cylinders are mounted radially round a circular crank-case2 the crank-shaft is fixed1 and the entire mass of cylinders and crank-case revolves around it as outlined at ,fig4 #bjj4 ,the explosive mixture and the lubricating oil are admitted through the fixed hollow crank-shaft1 passed into the explosion chamber through an automatic intake valve in the piston head in the early pattern1 and the spent gases exhausted through a mechanically operated valve in the cylinder head4 ,the course of the gases is practically a radial one4 ,a peculiarity of the construction of the motor is that nickel steel is used throughout4 ,aluminum is employed for the two oil pump housings2 the single compression ring known as the obdurator for each piston is made of brass2 there are three or four brass bushes2 gun metal is employed for certain pins--the rest is machined out of chrome nickel steel4 ,the crank-case is practically a steel hoop1 the depth depending on whether it has to receive seven-or fourteen-cylinders2 it has seven or fourteen holes bored as illustrated on its circumference4 ,when fourteen or eighteen cylinders are used the holes are bored in two distinct planes1 and offset in relation one to the other4 ,the cylinders of the small engine which have a bore of #d-c_/aj inches and a stroke of #d-g_/aj inches1 are machined out of the solid bar of steel until the thickness of the walls is only #a4e millimeters--4#jeije inch1 or practically #a_/af inch4 ,each one has twenty-two fins which gradually taper down as the region of greatest pressure is departed from4 ,in addition to carrying away heat1 the fins assist in strengthening the walls of the cylinder4 ,the barrel of the cylinder is slipped into the hole bored for it on the circumference of the crank-case and secured by a locking member in the nature of a stout compression ring1 sprung onto a groove on the base of the cylinder within the crank chamber4 ,on each lateral face of the crank chamber are seven holes1 drilled right through the chamber parallel with the crank-shaft4 ,each one of these holes receives a stout locking-pin of such a diameter that it presses against the split rings of two adjacent cylinders2 in addition each cylinder is fitted with a key-way4 ,this construction is not always followed1 some of the early ,gnome engines using the same system of cylinder retention as used on the latest monosoupape pattern4 ,the exhaust valve is mounted in the cylinder head1 ,fig4 #bja1 its seating being screwed in by means of a special box spanner4 ,on the fourteen-cylinder model the valve is operated directly by an overhead rocker arm with a gun metal rocker at its extremity coming in contact with the extremity of the valve stem4 ,as in standard motor car practice1 the valve is opened under the lift of the vertical push rod1 actuated by the cam4 ,the distinctive feature is the use of a four-blade leaf spring with a forked end encircling the valve stems and pressing against a collar on its extremity4 ,on the seven-cylinder model the movement is reversed1 the valve being opened on the downward pull of the push rod1 this lifting the outer extremity of the main rocker arm1 which tips a secondary and smaller rocker arm in direct contact with the extremity of the valve stem4 ,the springs are the same in each case4 ,the two types are compared at ,a and ,b1 ,fig4 #bjb4 ,illustration3 ,fig4 #bja4--,sectional ,view of ,early ,type ,gnome ,cylinder and ,piston ,showing ,construction and ,application of ,inlet and ,exhaust ,valves4 ,the pistons1 like the cylinders1 are machined out of the solid bar of nickel steel1 and have a portion of their wall cut away1 so that the two adjacent ones will not come together at the extremity of their stroke4 ,the head of the piston is slightly reduced in diameter and is provided with a groove into which is fitted a very light ,l-section brass split ring2 back of this ring and carried within the groove is sprung a light steel compression ring1 serving to keep the brass ring in expansion4 ,as already mentioned1 the intake valves are automatic1 and are mounted in the head of the piston as outlined at ,fig4 #bjb1 ,c4 ,the valve seating is in halves1 the lower portion being made to receive the wrist-pin and connecting rod1 and the upper portion1 carrying the valve1 being screwed into it4 ,the spring is composed of four flat blades1 with the hollowed stem of the automatic valve passing through their center and their two extremities attached to small levers calculated to give balance against centrifugal force4 ,the springs are naturally within the piston1 and are lubricated by splash from the crank chamber4 ,they are of a delicate construction1 for it is necessary that they shall be accurately balanced so as to have no tendency to fly open under the action of centrifugal force4 ,the intake valve is withdrawn by the use of special tools through the cylinder head1 the exhaust valve being first dismounted4 ,illustration3 ,fig4 #bjb4--;,details of ,old ,style ,gnome ,motor ,inlet and ,exhaust ,valve ,construction and ,operation4 ,the fourteen-cylinder motor shown at ,fig4 #bjc1 has a two-throw crank-shaft with the throws placed at #ahj degrees1 each one receiving seven connecting rods4 ,the parts are the same as for the seven-cylinder motor1 the larger one consisting of two groups placed side by side4 ,for each group of seven-cylinders there is one main connecting rod1 together with six auxiliary rods4 ,the main connecting rod1 which1 like the others1 is of ,h section1 has machined with it two ,l-section rings bored with six holes--#ea-a_/b degrees apart to take the six other connecting rods4 ,the cage of the main connecting rod carries two ball races1 one on either side1 fitting onto the crank-pin and receiving the thrust of the seven connecting rods4 ,the auxiliary connecting rods are secured in position in each case by a hollow steel pin passing through the two rings4 ,it is evident that there is a slightly greater angularity for the six shorter rods1 known as auxiliary connecting rods1 than for the longer main rods2 this does not appear to have any influence on the running of the motor4 ,illustration3 ,fig4 #bjc4--,the ,gnome ,fourteen-,cylinder #ajj ,horse-,power ,aviation ,engine4 ,coming to the manner in which the earliest design exhaust valves are operated on the old style motor1 this at first sight appears to be one of the most complicated parts of the motor1 probably because it is one in which standard practice is most widely departed from4 ,within the cylindrical casing bolted to the rear face of the crank-case are seven1 thin flat-faced steel rings1 forming female cams4 ,across a diameter of each ring is a pair of projecting rods fitting in brass guides and having their extremities terminating in a knuckle eye receiving the adjustable push rods operating the overhead rocker arms of the exhaust valve4 ,the guides are not all in the same plane1 the difference being equal to the thickness of the steel rings1 the total thickness being practically #b inches4 ,within the female cams is a group of seven male cams of the same total thickness as the former and rotating within them4 ,as the boss of the male cam comes into contact with the flattened portion of the ring forming the female cam1 the arm is pushed outward and the exhaust valve opened through the medium of the push-rod and overhead rocker4 ,this construction was afterwards changed to seven male cams and simple valve operating plunger and roller cam followers as shown at ,fig4 #bjd4 ,on the face of the crank-case of the fourteen-cylinder motor opposite to the valve mechanism is a bolted-on end plate1 carrying a pinion for driving the two magnetos and the two oil pumps1 and having bolted to it the distributor for the high-tension current4 ,each group of seven-cylinders has its own magneto and lubricating pump4 ,the two magnetos and the two pumps are mounted on the fixed platform carrying the stationary crank-shaft1 being driven by the pinion on the revolving crank chamber4 ,the magnetos are geared up in the proportion of #d to #g4 ,mounted on the end plate back of the driving pinion are the two high-tension distributor plates1 each one with seven brass segments let into it and connection made to the plugs by means of plain brass wire4 ,the wire passes through a hole in the plug and is then wrapped round itself1 giving a loose connection4 ,illustration3 ,fig4 #bjd4--;,cam and ,cam-,gear ,case of the ,gnome ,seven-,cylinder ,revolving ,engine4 ,illustration3 ,fig4 #bje4--;,diagrams ,showing ,why ,an ,odd ,number of ,cylinders is ,best for ,rotary ,cylinder ,motors4 ,a good many people doubtless wonder why rotary engines are usually provided with an odd number of cylinders in preference to an even number4 ,it is a matter of even torque1 as can easily be understood from the accompanying diagram4 ,fig4 #bje1 ,a1 represents a six-cylinder rotary engine1 the radial lines indicating the cylinders4 ,it is possible to fire the charges in two ways1 firstly1 in rotation1 #a1 #b1 #c1 #d1 #e1 #f1 thus having six impulses in one revolution and none in the next2 or alternately1 #a1 #c1 #e1 #b1 #d1 #f1 in which case the engine will have turned through an equal number of degrees between impulses #a and #c1 and #c and #e1 but a greater number between #e and #b1 even again between #b and #d1 #d and #f1 and a less number between #f and #a1 as will be clearly seen on reference to the diagram4 ,turning to ,fig4 #bje1 ,b1 which represents a seven-cylinder engine4 ,if the cylinders fire alternately it is obvious that the engine turns through an equal number of degrees between each impulse1 thus1 #a1 #c1 #e1 #g1 #b1 #d1 #f1 #a1 #c1 etc4 ,thus supposing the engine to be revolving1 the explosion takes place as each alternate cylinder passes1 for instance1 the point #a on the diagram1 and the ignition is actually operated in this way by a single contact4 ,illustration3 ,fig4 #bjf4--,simple ,carburetor ,used ,on ,early ,gnome ,engines ,attached to ,fixed ,crank-,shaft ,end4 ,the crank-shaft of the ,gnome1 as already explained1 is fixed and hollow4 ,for the seven- and nine-cylinder motors it has a single throw1 and for the fourteen- and eighteen-cylinder models has two throws at #ahj degrees4 ,it is of the built-up type1 this being necessary on account of the distinctive mounting of the connecting rods4 ,the carburetor shown at ,fig4 #bjf is mounted at one end of the stationary crank-shaft1 and the mixture is drawn in through a valve in the piston as already explained4 ,there is neither float chamber nor jet4 ,in many of the tests made at the factory it is said the motor will run with the extremity of the gasoline pipe pushed into the hollow crank-shaft1 speed being regulated entirely by increasing or decreasing the flow through the shut-off valve in the base of the tank4 ,even under these conditions the motor has been throttled down to run at #cej revolutions without misfiring4 ,its normal speed is #a1jjj to #a1bjj revolutions a minute4 ,castor oil is used for lubricating the engine1 the oil being injected into the hollow crank-shaft through slight-feed fittings by a mechanically operated pump which is clearly shown in sectional diagrams at ,fig4 #bjg4 ,illustration3 ,fig4 #bjg4--,sectional ,views of the ,gnome ,oil ,pump4 ,the ,gnome is a considerable consumer of lubricant1 the makers' estimate being #g pints an hour for the #ajj horse-power motor2 but in practice this is largely exceeded4 ,the gasoline consumption is given as #cjj to #cej grammes per horse-power4 ,the total weight of the fourteen-cylinder motor is #bbj pounds without fuel or lubricating oil4 ,its full power is developed at #a1bjj revolutions1 and at this speed about #i horse-power is lost in overcoming air resistance to cylinder rotation4 ,illustration3 ,fig4 #bjh4--,simplified ,diagram ,showing ,gnome ,motor ,magneto ,ignition ,system4 ,while the ,gnome engine has many advantages1 on the other hand1 the head resistance offered by a motor of this type is considerable2 there is a large waste of lubricating oil due to the centrifugal force which tends to throw the oil away from the cylinders2 the gyroscopic effect of the rotary motor is detrimental to the best working of the aeroplane1 and moreover it requires about seven per cent4 of the total power developed by the motor to drive the revolving cylinders around the shaft4 ,of necessity1 the compression of this type of motor is rather low1 and an additional disadvantage manifests itself in the fact that there is as yet no satisfactory way of muffling the rotary type of motor4 ,,gnome ,,monosoupape ,,type ,the latest type of ,gnome engine is known as the monosoupape type because but one valve is used in the cylinder head1 the inlet valve in the piston being dispensed with on account of the trouble caused by that member on earlier engines4 ,the construction of this latest type follows the lines established in the earlier designs to some extent and it differs only in the method of charging4 ,the very rich mixture of gas and air is forced into the crank-case through the jet inside the crank-shaft1 and enters the cylinder when the piston is at its lowest position1 through the half-round openings in the guiding flange and the small holes or ports machined in the cylinder and clearly shown at ,fig4 #baj4 ,the returning piston covers the port1 and the gas is compressed and fired in the usual way4 ,the exhaust is through a large single valve in the cylinder head1 which gives rise to the name monosoupape1 or single-valve motor1 and this valve also remains open a portion of the intake stroke to admit air into the cylinder and dilute the rich gas forced in from the crank-case interior4 ,aviators who have used the early form of ,gnome say that the inlet valve in the piston type was prone to catch on fire if any valve defect materialized1 but the monosoupape pattern is said to be nearly free of this danger4 ,the bore of the #ajj horse-power nine-cylinder engine is #aaj mm41 the piston stroke #aej mm4 ,extremely careful machine work and fitting is necessary4 ,in many parts1 tolerances of less than 4#jjjd 7four ten thousandths of an inch7 are all that are allowed4 ,this is about one-sixth the thickness of the average human hair1 and in other parts the size must be absolutely standard1 no appreciable variation being allowable4 ,the manufacture of this engine establishes new mechanical standards of engine production in this country4 ,much machine work is needed in producing the finished components from the bar and forging4 ,illustration3 ,fig4 #bji4--,the ,g4 ,v4 ,gnome ,monosoupape ,nine-,cylinder ,rotary ,engine ,mounted on ,testing ,stand4 ,illustration3 ,fig4 #baj4--,sectional ,view ,showing ,construction of ,general ,vehicle ,co4 ,monosoupape ,gnome ,engine4 ,the cylinders1 for example1 are machined from #f inch solid steel bars1 which are sawed into blanks #aa inches in length and weighing about #ig pounds4 ,the first operation is to drill a #b-a_/af inch hole through the center of the block4 ,a heavy-duty drilling machine performs this work1 then the block goes to the lathe for further operations4 ,fig4 #baa shows six stages of the progress of a cylinder1 a few of the intermediate steps being omitted4 ,these give1 however1 a good idea of the work done4 ,the turning of the gills1 or cooling flanges1 is a difficult proposition1 owing to the depth of the cut and the thin metal that forms the gills4 ,this operation requires the utmost care of tools and the use of a good lubricant to prevent the metal from tearing as the tools approach their full depth4 ,these gills are only #j4f mm41 or #j4jbcg in41 thick at the top1 tapering to a thickness of #a4d mm4 7#j4jeec in47 at the base1 and are #af mm4 7#j4fcb in47 deep4 ,when the machine work is completed the cylinder weighs but #e-a_/b pounds4 ,illustration3 ,fig4 #baa4--;,how a ,gnome ,cylinder is ,reduced from ,solid ,chunk of ,steel ,weighing #ig ,pounds to ,finished ,cylinder ,weighing #e-a_/b ,pounds4 ,,gnome ,,fuel ,,system1 ,,ignition ,,and ,,lubrication ,the following description of the fuel supply1 ignition and oiling of the monosoupape1 or single valve ,gnome1 is taken from ,the ,automobile4 ,gasoline is fed to the engine by means of air pressure at #e pounds per sq4 in41 which is produced by the air pump on the engine clearly shown at ,fig4 #baj4 ,a pressure gauge convenient to the operator indicates this pressure1 and a valve enables the operator to control it4 ,no carburetor is used4 ,the gasoline flows from the tank through a shut-off valve near the operator and through a tube leading through the hollow crank-shaft to a spray nozzle located in the crank-case4 ,there is no throttle valve1 and as each cylinder always receives the same amount of air as long as the atmospheric pressure is the same1 the output cannot be varied by reducing the fuel supply1 except within narrow limits4 ,a fuel capacity of #fe gallons is provided4 ,the fuel consumption is at the rate of #ab ,u4 ,s4 gallons per hour4 ,the high-tension magnetos1 with double cam or two break per revolution interrupter1 is located on the thrust plate in an inverted position1 and is driven at such a speed as to produce nine sparks for every two revolutions2 that is1 at #b-a_/d times engine speed4 ,a ,splitdorf magneto is fitted4 ,there is no distributor on the magneto4 ,the high-tension collector brush of the magneto is connected to a distributor brush holder carried in the bearer plate of the engine4 ,the brush in this brush holder is pressed against a distributor ring of insulating material molded in position in the web of a gear wheel keyed to the thrust plate1 which gear serves also for starting the engine by hand4 ,molded in this ring of insulating material are nine brass contact sectors1 connecting with contact screws at the back side of the gear1 from which bare wires connect to the spark-plugs4 ,the distributor revolves at engine speed1 instead of at half engine speed as on ordinary engines1 and the distributor brush is brought into electrical connection with each spark-plug every time the piston in the cylinder in which this spark-plug is located approaches the outer dead center4 ,however1 on the exhaust stroke no spark is being generated in the magneto1 hence none is produced at the spark-plug4 ,illustration3 ,fig4 #bab4--,the ,gnome ,engine ,cam-,gear ,case1 a ,fine ,example of ,accurate ,machine ,work4 ,ordinarily the engine is started by turning on the propeller1 but for emergency purposes as in seaplanes or for a quick get away if landing inadvertently in enemy territory1 a hand starting crank is provided4 ,this is supported in bearings secured to the pressed steel carriers of the engine and is provided with a universal joint between the two supports so as to prevent binding of the crank in the bearings due to possible distortion of the supports4 ,the gear on this starting crank and the one on the thrust plate with which it meshes are cut with helical teeth of such hand that the starting pinion is thrown out of mesh as soon as the engine picks up its cycle4 ,a coiled spring surrounds part of the shaft of the starting crank and holds it out of gear when not in use4 ,illustration3 ,fig4 #bac4--;,g4 ,v4 ,gnome ,monosoupape1 with ,cam-,case ,cover ,removed to ,show ,cams and ,valve-,operating ,plungers with ,roller ,cam ,followers4 ,lubricating oil is carried in a tank of #be gallon capacity1 and if this tank has to be placed in a low position it is connected with the air-pressure line1 so that the suction of the oil pump is not depended upon to get the oil to the pump4 ,from the bottom of the oil tank a pipe leads to the pump inlet4 ,there are two outlets from the pump1 each entering the hollow crank-shaft1 and there is a branch from each outlet pipe to a circulation indicator convenient to the operator4 ,one of the oil leads feeds to the housing in the thrust plate containing the two rear ball bearings1 and the other lead feeds through the crank-pin to the cams1 as already explained4 ,owing to the effect of centrifugal force and the fact that the oil is not used over again1 the oil consumption of a revolving cylinder engine is considerably higher than that of a stationary cylinder engine4 ,fuel consumption is also somewhat higher1 and for this reason the revolving cylinder engine is not so well suited for types of airplanes designed for long trips1 as the increased weight of supplies required for such trips1 as compared with stationary cylinder type motors1 more than offsets the high weight efficiency of the engine itself4 ,but for short trips1 and especially where high speed is required1 as in single seated scout and battle planes or avions de chasse1 as the ,french say1 the revolving cylinder engine has the advantage4 ,the oil consumption of the ,gnome engine is as high as #b4d gallon per hour4 ,castor oil is used for lubrication because it is not cut by the gasoline mist present in the engine interior as an oil of mineral derivation would be4 ,,german ,,gnome ,,type ,,engine ,illustration3 ,fig4 #bad4--,the #ej ,horse-,power ,rotary ,bayerischen ,motoren ,gesellschaft ,engine1 a ,german ,adaptation of the ,early ,gnome ,design4 ,a ,german adaptation of the ,gnome design is shown at ,fig4 #bad4 ,this is known as the ,bayerischen ,motoren ,gesellschaft engine and the type shown is an early design rated at #ej horse-power4 ,the bore is #aaj mm41 the stroke is #abj mm41 and it is designed to run at a speed of #a1bjj ,r4 ,p4 ,m4 ,it is somewhat similar in design to the early ,gnome valve-in-piston design except that two valves are carried in the piston top instead of one4 ,the valve operating arrangement is different also1 as a single four point cam is used to operate the seven exhaust valves4 ,it is driven by epicyclic gearing1 the cam being driven by an internal gear machined integrally with it1 the cam being turned at #g_/h times the engine speed4 ,another feature is the method of holding the cylinders on the crank-case4 ,the cylinder is provided with a flange that registers with a corresponding member of the same diameter on the crank-case4 ,a ,u section1 split clamping ring is bolted in place as shown1 this holding both flanges firmly together and keeping the cylinder firmly seated against the crank-case flange4 ,the monosoupape type has also been copied and has received some application in ,germany1 but the most successful ,german airplanes are powered with six-cylinder vertical engines such as the ,benz and ,mercedes4 ,,the ,,le ,,rhone ,,motor ,the ,le ,rhone motor is a radial revolving cylinder engine that has many of the principles which are incorporated in the ,gnome but which are considered to be an improvement by many foreign aviators4 ,instead of having but one valve in the cylinder head1 as the latest type monosoupape ,gnome has1 the ,le ,rhone has two valves1 one for intake and one for exhaust in each cylinder4 ,by an ingenious rocker arm and tappet rod arrangement it is possible to operate both valves with a single push rod4 ,inlet pipes communicate with the crank-case at one end and direct the fresh gas to the inlet valve cage at the other4 ,another peculiarity in the design is the method of holding the cylinders in place4 ,instead of having a vertically divided crank-case as the ,gnome engine has and clamping both halves of the case around the cylinders1 the crank-case of the ,le ,rhone engine is in the form of a cylinder having nine bosses provided with threaded openings into which the cylinders are screwed4 ,a thread is provided at the base of each cylinder and when the cylinder has been screwed down the proper amount it is prevented from further rotation about its own axis by a substantial lock nut which screws down against the threaded boss on the crank-case4 ,the external appearance of the ,le ,rhone type motor is clearly shown at ,fig4 #bae1 while the general features of construction are clearly outlined in the sectional views given at ,figs4 #baf and #bag4 ,illustration3 ,fig4 #bae--,nine-,cylinder ,revolving ,le ,rhone ,type ,aviation ,engine4 ,illustration3 ,fig4 #baf4--,part ,sectional ,views of ,le ,rhone ,rotary ,cylinder ,engine1 ,showing ,method of ,cylinder ,retention1 ,valve ,operation and ,novel ,crank ,disc ,assembly4 ,illustration3 ,fig4 #bag4--,side ,sectional ,view of ,le ,rhone ,aviation ,engine4 ,illustration3 ,fig4 #bah4--,view ,showing ,le ,rhone ,valve ,action and ,connecting ,rod ,big ,end ,arrangement4 ,the two main peculiarities of this motor are the method of valve actuation by two large cams and the distinctive crank-shaft and connecting rod big end construction4 ,the connecting rods are provided with feet or shoes on the end which fit into grooves lined with bearing metal which are machined into crank discs revolving on ball bearings and which are held together so that the connecting rod big ends are sandwiched between them by clamping screws4 ,this construction is a modification of that used on the ,anzani six-cylinder radial engine4 ,there are three grooves machined in each crank disc and three connecting rod big ends run in each pair of grooves4 ,the details of this construction can be readily ascertained by reference to explanatory diagrams at ,figs4 #bah and #bai1 ,a4 ,three of the rods which work in the groove nearest the crank-pin are provided with short shoes as shown at ,fig4 #bai1 ,b4 ,the short shoes are used on the rods employed in cylinders number #a1 #d1 and #g4 ,the set of connecting rods that work in the central grooves are provided with medium-length shoes and actuate the pistons in cylinders numbers #c1 #f1 and #i4 ,the three rods that work in the outside grooves have still longer shoes and are employed in cylinders numbers #b1 #e1 and #h4 ,the peculiar profile of the inlet and exhaust cam plates are shown at ,c1 ,fig4 #bai1 while the construction of the wrist-pin1 wrist-pin bushing and piston are clearly outlined at the sectional view at ,e4 ,the method of valve actuation is clearly outlined at ,fig4 #bbj1 which shows an end section through the cam case and also a partial side elevation showing one of the valve operating levers which is fulcrumed at a central point and which has a roller at one end bearing on one cam while the roller or cam follower at the other end bears on the other cam4 ,the valve rocker arm actuating rod is1 of course1 operated by this simple lever and is attached to it in such a way that it can be pulled down to depress the inlet valve and pushed up to open the exhaust valve4 ,illustration3 ,fig4 #bai4--;,diagrams ,showing ,important ,components of ,le ,rhone ,motor4 ,illustration3 ,fig4 #bbj4--;,how the ,cams of the ,le ,rhone ,motor ,can ,operate ,two ,valves with a ,single ,push ,rod4 ,a carburetor of peculiar construction is employed in the ,le ,rhone engine1 this being a very simple type as outlined at ,fig4 #bba4 ,it is attached to the threaded end of the hollow crank-shaft by a right and left coupling4 ,the fuel is pumped to the spray nozzle1 the opening in which is controlled by a fuel regulating needle having a long taper which is lifted out of the jet opening when the air-regulating slide is moved4 ,the amount of fuel supplied the carburetor is controlled by a special needle valve fitting which combines a filter screen and which is shown at ,b4 ,in regulating the speed of the ,le ,rhone engine1 there are two possible means of controlling the mixture1 one by altering the position of the air-regulating slide1 which also works the metering needle in the jet1 and the other by controlling the amount of fuel supplied to the spray nozzle through the special fitting provided for that purpose4 ,illustration3 ,fig4 #bba4--,the ,le ,rhone ,carburetor at ,a and ,fuel ,supply ,regulating ,device at ,b4 ,in considering the action of this engine one can refer to ,fig4 #bbb4 ,the crank ,o4 ,m4 is fixed1 while the cylinders can turn about the crank-shaft center ,o and the piston turns around the crank-pin ,m1 because of the eccentricity of the centers of rotation the piston will reciprocate in the cylinders4 ,this distance is at its maximum when the cylinder is above ,o and at a minimum when it is above ,m1 and the difference between these two positions is equal to the stroke1 which is twice the distance of the crank-throw ,o1 ,m4 ,the explosion pressure resolves itself into the force ,f exerted along the line of the connecting rod ,a1 ,m1 and also into a force ,n1 which tends to make the cylinders rotate around point ,o in the direction of the arrow4 ,an odd number of cylinders acting on one crank-pin is desirable to secure equally spaced explosions1 as the basic action is the same as the ,gnome engine4 ,illustration3 ,fig4 #bbb4--;,diagrams ,showing ,le ,rhone ,motor ,action and ,firing ,order4 ,the magneto is driven by a gear having #cf teeth attached to crank-case which meshes with #af-tooth pinion on armature4 ,the magneto turns at #b4be times crank-case speed4 ,two cams1 one for inlet1 one for exhaust1 are mounted on a carrying member and act on nine rocker arms which are capable of giving a push-and-pull motion to the valve-actuating rocker-operating rods4 ,a gear driven by the crank-case meshes with a larger member having internal teeth carried by the cam carrier4 ,each cam has five profiles and is mounted in staggered relation to the other4 ,these give the nine fulcrumed levers the proper motion to open the inlet and exhaust valves at the proper time4 ,the cams are driven at #de_/ej or #i_/aj of the motor speed4 ,the cylinder dimensions and timing follows2 the weight can be approximated by figuring #c pounds per horse-power4 #hj ,h4,p4 #aje ,m_/,m bore #d4bj bore4 #adj ,m_/,m stroke #e4fj stroke4 #aaj ,h4,p4 #aab ,m_/,m bore #d4dh bore4 #agj ,m_/,m stroke #f4hj stroke4 ,timing--,intake valve opening1 lag #ah deg4 #ah deg4 ,intake valve closing1 lag #ce deg4 #ce deg4 ,exhaust valve opening1 lead #ee deg4 #aaj ,h4,p4 #de deg4 #hj ,h4,p4 ,exhaust valve closing1 lag #e deg4 #e deg4 ,ignition time advance #bf deg4 #bf deg4 ,illustration3 ,fig4 #bbc4--;,diagram ,showing ,positions of ,piston in ,le ,rhone ,rotary ,cylinder ,motor4 ,,the ,,renault ,,air-,,cooled ,,vee ,,engine ,illustration3 ,fig4 #bbd4--;,diagrams ,showing ,valve ,timing of ,le ,rhone ,aviation ,engine4 ,illustration3 ,fig4 #bbe4--;,diagrams ,showing ,how ,cylinder ,cooling is ,effected in ,renault ,vee ,engines4 ,air-cooled stationary engines are rarely used in airplanes1 but the ,renault ,freres of ,france have for several years manufactured a complete series of such engines of the general design shown at ,fig4 #bbe1 ranging from a low-powered one developed eight or nine years ago and rated at #dj and #ej horse-power1 to later eight-cylinder models rated at #gj horse-power and a twelve-cylinder1 or twin six1 rated at #ij horse-power4 ,the cylinders are of cast iron and are furnished with numerous cooling ribs which are cast integrally4 ,the cylinder heads are separate castings and are attached to the cylinder as in early motorcycle engine practice1 and serve to hold the cylinder in place on the aluminum alloy crank-case by a cruciform yoke and four long hold-down bolts 7,fig4 #bbf74 ,the pistons are of cast steel and utilize piston rings of cast iron4 ,the valves are situated on the inner side of the cylinder head1 the arrangement being unconventional in that the exhaust valves are placed above the inlet4 ,the inlet valves seat in an extension of the combustion head and are actuated by direct push rod and cam in the usual manner while an overhead gear in which rockers are operated by push rods is needed to actuate the exhaust valves4 ,the valve action is clearly shown in ,figs4 #bbf and #bbg4 ,the air stream by which the cylinders are cooled is produced by a centrifugal or blower type fan of relatively large diameter which is mounted on the end of a crank-shaft and the air blast is delivered from this blower into an enclosed space between the cylinder from which it escapes only after passing over the cooling fins4 ,in spite of the fact that considerable prejudice exists against air-cooling fixed cylinder engines1 the ,renault has given very good service in both ,england and ,france4 ,illustration3 ,fig4 #bbf4--;,end ,sectional ,view of ,renault ,air-,cooled ,aviation ,engine4 ,illustration3 ,fig4 #bbg4--,side ,sectional ,view of ,renault ,twelve-,cylinder ,air-,cooled ,aviation ,engine ,crank-,case1 ,showing ,use of ,plain and ,ball ,bearings for ,crank-,shaft ,support4 ,as will be seen by the sectional view at ,fig4 #bbg1 the steel crank-shaft is carried in a combination of plain bearings inside the crank-case and by ball bearings at the ends4 ,owing to air cooling1 special precautions are taken with the lubrication system1 though the lubrication is not forced or under high pressure4 ,an oil pump of the gear-wheel type delivers oil from the sump at the bottom of the crank-case to a chamber above1 from which the oil flows by gravity along suitable channels to the various main bearings4 ,it flows from the bearings into hollow rings fastened to the crank-webs1 and the oil thrown from the whirling connecting rod big ends bathes the internal parts in an oil mist4 ,in the eight-cylinder designs ignition is effected by a magneto giving four sparks per revolution and is accordingly driven at engine speed4 ,in the twelve-cylinder machine two magnetos of the ordinary revolving armature or two-spark type1 each supplying six cylinders1 are fitted as outlined at ,fig4 #bbh4 ,the carburetor is a float feed form4 ,warm air is supplied for ,winter and damp weather by air pipes surrounding the exhaust pipes4 ,the normal speed of the ,renault engine is #a1hjj ,r4 ,p4 ,m41 but as the propeller is mounted upon an extension of the cam-shaft the normal propeller speed is but half that of the engine1 which makes it possible to use a propeller of large diameter and high efficiency4 ,owing to the air cooling1 but low compression may be used1 this being about #fj pounds per square inch1 which1 of course1 lowers the mean effective pressure and makes the engine less efficient than water-cooled forms where it is possible to use compression pressure of #ajj or more pounds per square inch4 ,the #gj horse-power engine has cylinders with a bore of #c4gh inches and a stroke of #e4eb inches4 ,its weight is given as #cif pounds1 when in running order1 which figures #e4g pounds per horse-power4 ,the same cylinder size is used on the twelve-cylinder #ajj horse-power and the stroke is the same4 ,this engine in running order weighs #fch pounds1 which figures approximately #f4d pounds per ,b4 ,h4 ,p4 ,illustration3 ,fig4 #bbh4--;,end ,view of ,renault ,twelve-,cylinder ,engine ,crank-,case1 ,showing ,magneto ,mounting4 ,illustration3 ,fig4 #bbi4--;,diagram ,outlining ,renault ,twelve-,cylinder ,engine ,ignition ,system4 ,,simplex ,,model ,a ,,hispano-,,suiza ,the ,model ,a is of the water-cooled four-cycle ,vee type1 with eight cylinders1 #d4gbde inch bore by #e4aahb inch stroke1 piston displacement #gah cubic inches4 ,at sea-level it develops #aej horse-power at #a1dej ,r4 ,p4 ,m4 ,it can be run successfully at much higher speeds1 depending on propeller design and gearing1 developing proportionately increased power4 ,the weight1 including carburetor1 two magnetos1 propeller hub1 starting magneto and crank1 but without radiator1 water or oil or exhaust pipes1 is #dde pounds4 ,average fuel consumption is 4#e pound per horse-power hour and the oil consumption at #a1dej ,r4 ,p4 ,m4 is three quarts per hour4 ,the external appearance is shown at ,fig4 #bcj4 ,four cylinders are contained in each block1 which is of built-up construction2 the water jackets and valve ports are cast aluminum and the individual cylinders heat-treated steel forgings threaded into the bored holes of the aluminum castings4 ,each block after assembly is given a number of protective coats of enamel1 both inside and out1 baked on4 ,coats on the inside are applied under pressure4 ,the pistons are aluminum castings1 ribbed4 ,connecting rods are tubular1 of the forked type4 ,one rod bears directly on the crank-pin2 the other rod has a bearing on the outside of the one first mentioned4 ,the crank-shaft is of the five-bearing type1 very short1 stiff in design1 bored for lightness and for the oiling system4 ,the crank-shaft extension is tapered for the ,french standard propeller hub1 which is keyed and locked to the shaft4 ,this makes possible instant change of propellers4 ,the case is in two halves divided on the center line of the crank-shaft1 the bearings being fitted between the upper and lower sections4 ,the lower half is deep1 providing a large oil reservoir and stiffening the engine4 ,the upper half is simple and provides magneto supports on extension ledges of the two main faces4 ,the valves are of large diameter with hollow stems1 working in cast iron bushings4 ,they are directly operated by a single hollow cam-shaft located over the valves4 ,the cam-shafts are driven from the crank-shaft by vertical shafts and bevel gears4 ,the cam-shafts1 cams and heads of the valve stems are all enclosed in oil-tight removable housings of cast aluminum4 ,illustration3 ,fig4 #bcj4--,the ,simplex ,model ,a ,hispano-,suiza ,aviation ,engine1 a ,very ,successful ,form4 ,oiling is by a positive pressure system4 ,the oil is taken through a filter and steel tubes cast in the case to main bearings1 through crank-shaft to crank-pins4 ,the fourth main bearing is also provided with an oil lead from the system and through tubes running up the end of each cylinder block1 oil is provided for the cam-shafts1 cams and bearings4 ,the surplus oil escapes through the end of the cam-shaft where the driving gears are mounted1 and with the oil that has gathered in the top casing1 descends through the drive shaft and gears to the sump4 ,ignition is by two eight-cylinder magnetos firing two spark-plugs per cylinder4 ,the magnetos are driven from each of the two vertical shafts by small bevel pinions meshing in bevel gears4 ,the carburetor is mounted between the two cylinder blocks and feeds the two blocks through aluminum manifolds which are partly water-jacketed4 ,the engine can be equipped with a geared hand crank-starting device4 ,,sturtevant ,,model #e;,a #adj ,,horse-,,power ,,engine ,these motors are of the eight-cylinder ,v type1 four-stroke cycle1 water-cooled1 having a bore of #d inches and a stroke of #e-a_/b inches1 equivalent to #ajb mm4 x #adj mm4 ,the normal operating speed of the crank-shaft is #b1jjj ,r4 ,p4 ,m4 ,the propeller shaft is driven through reducing gears which can be furnished in different gear ratios4 ,the standard ratio is #e3c1 allowing a propeller speed of #a1bjj ,r4 ,p4 ,m4 ,the construction of the motor is such as to permit of the application of a direct drive4 ,the change from the direct drive to gear drive1 or vice versa1 can be accomplished in approximately one hour4 ,the cylinders are cast in pairs from an aluminum alloy and are provided with steel sleeves1 carefully fitted into each cylinder4 ,a perfect contact is secured between cylinder and sleeve2 at the same time a sleeve can be replaced without injury to the cylinder proper4 ,no difficulties due to expansion occur on account of the rapid transmission of heat and the fact that the sleeve is always at higher temperature than the cylinder4 ,a moulded copper asbestos gasket is placed between the cylinder and the head1 permitting the cooling water to circulate freely and at the same time insuring a tight joint4 ,the cylinder heads are cast in pairs from an aluminum alloy and contain ample water passages for circulation of cooling water over the entire head4 ,trouble due to hot valves is thereby eliminated1 a most important consideration in the operation of an aeroplane motor4 ,the water jacket of the head corresponds to the water jacket of the cylinders and large openings in both allow the unobstructed circulation of the cooling water4 ,the cylinder heads and cylinders are both held to the base by six long bolts4 ,the valves are located in the cylinder heads and are mechanically operated4 ,the valves and valve springs are especially accessible and of such size as to permit high volumetric efficiency4 ,the valves are constructed of hardened tungsten steel1 the heads and stems being made from one piece4 ,the valve rocker arms located on the top of the cylinder are provided with adjusting screws4 ,a check nut enables the adjusting screw to be securely locked in position1 once the correct clearance has been determined4 ,the rocker arm bearings are adequately lubricated by a compression grease cup4 ,cam-rollers are interposed between the cams and the push rods in order to reduce the side thrust on the push rods4 ,a system of double springs is employed which greatly reduces the stress on each spring and insures utmost reliability4 ,a spring of extremely large diameter returns the valve2 a second spring located at the cylinder base handles the push rod linkage4 ,these springs1 which operate under low stress1 are made from the best of steel and are given a special double heat treatment4 ,the pistons are made from a special aluminum alloy2 are deeply ribbed in the head for cooling and strength and provided with two piston rings4 ,these pistons are exceedingly light weight in order to minimize vibration and prevent wear on the bearings4 ,the piston pin is made of chrome nickel steel1 bored hollow and hardened4 ,it is allowed to turn1 both in piston and connecting rod4 ,the piston rings are of special design1 developed after years of experimenting in aeronautical engines4 ,the connecting rods are of ,h section1 machined all over from forgings of a special air-hardening chrome nickel steel which1 after being heat treated has a tensile strength of #bhj1jjj pounds per square inch4 ,they are consequently very strong and yet unusually light1 and being machined all over are of absolutely uniform section1 which gives as nearly perfect balance as can be obtained4 ,the big ends are lined with white metal and the small ends are bushed with phosphor bronze4 ,the connecting rods are all alike and take their bearings side by side on the crank-pin1 the cylinders being offset to permit of this arrangement4 ,the crank-shaft is machined from the highest grade chrome nickel steel1 heat treated in order to obtain the best properties of this material4 ,it is #b-a_/d inches in diameter 7#eg mm47 and bored hollow throughout1 insuring maximum strength with minimum weight4 ,it is carried in three large1 bronze-backed white metal bearings4 ,a new method of producing these bearings insures a perfect bond between the two metals and eliminates breakage4 ,the base is cast from an aluminum alloy4 ,great strength and rigidity is combined with light weight4 ,the sides extend considerably below the center line of the crank-shaft1 providing an extremely deep section4 ,at all highly stressed points1 deep ribs are provided to distribute the load evenly and eliminate bending4 ,the lower half of the base is of cast aluminum alloy of extreme lightness4 ,this collects the lubricating oil and acts as a small reservoir for same4 ,an oil-filtering screen of large area covers the entire surface of the sump4 ,the propeller shaft is carried on two large annular ball bearings driven from the crank-shaft by hardened chrome nickel steel spur gears4 ,these gears are contained within an oil-tight casing integral with the base on the opposite end from the timing gears4 ,a ball-thrust bearing is provided on the propeller shaft to take the thrust of a propeller or tractor1 as the case may be4 ,in case of the direct drive a stub shaft is fastened direct to the crank-shaft and is fitted with a double thrust bearing4 ,the cam-shaft is contained within the upper half of the base between the two groups of cylinders1 and is supported in six bronze bearings4 ,it is bored hollow throughout and the cams are formed integral with the shaft and ground to the proper shape and finish4 ,an important development in the shape of cams has resulted in a maintained increase of power at high speeds4 ,the gears operating the cam-shaft1 magneto1 oil and water pumps are contained within an oil-tight casing and operate in a bath of oil4 ,lubrication is of the complete forced circulating system1 the oil being supplied to every bearing under high pressure by a rotary pump of large capacity4 ,this is operated by gears from the crank-shaft4 ,the oil passages from the pump to the main bearings are cast integral with the base1 the hollow crank-shaft forming a passage through the connecting rod bearings and the hollow cam-shaft distributing the oil to the cam-shaft bearings4 ,the entire surface of the lower half of the base is covered with a fine mesh screen through which the oil passes before reaching the pump4 ,approximately one gallon of oil is contained within the base and this is continually circulated through an external tank by a secondary pump operated by an eccentric on the cam-shaft4 ,this also draws fresh oil from the external tank which can be made of any desired capacity4 ,,specifications--,,model #e;,a ,,type #h ,horse-power rating1 #adj at #b1jjj ,r4 ,p4 ,m4 ,bore1 #d inches #ajb mm4 ,stroke1 #e-a_/b inches #adj mm4 ,number of cylinders1 #h4 ,arrangement of cylinders1 ,v4 ,cooling1 water4 ,circulation by centrifugal pump4 ,cycle1 four stroke4 ,ignition 7double71 #b ,bosch or ,splitdorf magnetos4 ,carburetor1 ,zenith duplex4 ,water jacket manifold4 ,oiling system1 complete forced4 ,circulating gear pump4 ,normal crank-shaft speed1 #b1jjj ,r4 ,p4 ,m4 ,propeller shaft1 #c_/e crank-shaft speed at normal1 #a1bjj ,r4 ,p4 ,m4 ,stated power at #cj barometer1 #adj ,b4 ,h4 ,p4 ,stated weight with all accessories but without water1 gasoline or oil1 #ead pounds #bcd kilos4 ,weight per ,b4 ,h4 ,p41 #c4g pounds #a4fh kilos4 ,stated weight with all accessories with water1 #eej pounds #bej kilos4 ,weight per ,b4 ,h4 ,p4 with water1 #c4ie pounds #a4gi kilos4 ,,the ,,curtiss ,,aviation ,,motors ,the ,curtiss ,,ox motor has eight cylinders1 #d-;inch bore1 #e-;inch stroke1 delivers #ij horse-power at #a1djj turns1 and the weight turns out at #d4ag pounds per horse-power4 ,this motor has cast iron cylinders with monel metal jackets1 overhead inclined valves operated by means of two rocker arms1 push-and-pull rods from the central cam-shaft located in the crank-case4 ,the cam and push rod design is extremely ingenious and the whole valve construction turns out very light4 ,this motor is an evolution from the early ,curtiss type motor which was used by ,glenn ,curtiss when he won the ,gordon ,bennett ,cup at ,rheims4 ,a slightly larger edition of this type motor is the ,,oxx-#e1 as shown at ,figs4 #bca and #bcb1 which has cylinders #d-a_/d inches by #e inches1 delivers #ajj horse-power at #a1djj turns and has the same fuel and oil consumption as the ,,ox type motor1 namely1 4#fj pound of fuel per brake horse-power hour and 4#jc pound of lubricating oil per brake horse-power hour4 ,illustration3 ,fig4 #bca4--,the ,curtiss ,,oxx-#e ,aviation ,engine is an ,eight-,cylinder ,type ,largely ,used on ,training ,machines4 ,the ,curtiss ,company have developed in the last two years a larger-sized motor now known as the ,v-#b1 which was originally rated at #afj horse-power and which has since been refined and improved so that the motor gives #bbj horse-power at #a1djj turns1 with a fuel consumption of #eb_/ajj of a pound per brake horse-power hour and an oil consumption of 4#jb of a pound per brake horse-power hour4 ,this larger motor has a weight of #c4de pounds per horse-power and is now said to be giving very satisfactory service4 ,the ,v-#b motor has drawn steel cylinders1 with a bore of #e inches and a stroke of #g inches1 with a steel water jacket top and a monel metal cylindrical jacket1 both of which are brazed on to the cylinder barrel itself4 ,both these motors use side by side connecting rods and fully forced lubrication4 ,the cam-shafts act as a gallery from which the oil is distributed to the cam-shaft bearings1 the main crank-shaft bearings1 and the gearing4 ,here again we find extremely short rods1 which1 as before mentioned1 enables the height and the consequent weight of construction to be very much reduced4 ,for ordinary flying at altitudes of #e1jjj to #f1jjj feet1 the motors are sent out with an aluminum liner1 bolted between the cylinder and the crank-case in order to give a compression ratio which does not result in pre-ignition at a low altitude4 ,for high flying1 however1 these aluminum liners are taken out and the compression volume is decreased to about #ah4f per cent4 of the total volume4 ,illustration3 ,fig4 #bcb4--,top and ,bottom ,views of the ,curtiss ,,oxx-#e #ajj ,horse-,power ,aviation ,engine4 ,the ,curtiss ,aeroplane ,company announces that it has recently built1 and is offering1 a twelve-cylinder #e x #g motor1 which was designed for aeronautical uses primarily4 ,this engine is rated at #bej horse-power1 but it is claimed to develop #cjj at #a1djj ,r4 ,p4 ,m4 ,weights--,motor1 #a1abe pounds2 radiator1 #abj pounds2 cooling water1 #ajj pounds2 propeller1 #ie pounds4 ,gasoline ,consumption per ,horse-power ,hour1 #f_/aj pounds4 ,oil ,consumption per ,hour at ,maximum ,speed--#b pints4 ,installation ,dimensions--,overall length1 #hd-e_/h inches2 overall width1 #cd-a_/h inches2 overall depth1 #dj inches2 width at bed1 #cj-a_/b inches2 height from bed1 #ba-a_/h inches2 depth from bed1 #ah-a_/b inches4 ,,thomas-,,morse ,,model #hh ,,engine ,the ,thomas-,morse ,aircraft ,corporation of ,ithaca1 ,n4 ,y41 has produced a new engine1 ,model #hh1 bearing a close resemblance to the earlier model4 ,the main features of that model have been retained2 in fact1 many parts are interchangeable in the two engines4 ,supported by the great development in the wide use of aluminum1 the ,thomas engineers have adopted this material for cylinder construction1 which adoption forms the main departure from previous accepted design4 ,the marked tendency to-day toward a higher speed of rotation has been conclusively justified1 in the opinion of the ,thomas engineers1 by the continued reliable performance of engines with crank-shafts operating at speeds near #b1jjj revolutions per minute1 driving the propeller through suitable gearing at the most efficient speed4 ,high speed demands that the closest attention be paid to the design of reciprocating and rotating parts and their adjacent units4 ,steel of the highest obtainable tensile strength must be used for connecting rods and piston pins1 that they may be light and yet retain a sufficient factor of safety4 ,piston design is likewise subjected to the same strict scrutiny4 ,at the present day1 aluminum alloy pistons operate so satisfactorily that they may be said to have come to stay4 ,the statement often made in the past1 that the gearing down of an engine costs more in the weight of reduction gears and propeller shaft than is warranted by the increase in horse-power1 is seldom heard to-day4 ,the mean effective pressure remaining the same1 the brake horse-power of any engine increases as the speed4 ,that is1 an engine delivering #ajj brake horse-power at #a1ejj revolutions per minute will show #acc brake horse-power at #b1jjj revolutions per minute1 an increase of #cc brake horse-power4 ,to utilize this increase in horse-power1 a matter of some fifteen pounds must be spent in gearing and another fifteen perhaps on larger valves1 bearings1 etc4 ,two per cent4 may be assumed lost in the gears4 ,in other words1 the increase in horse-power due to increasing the speed has been attained at the expense of about one pound per brake horse-power4 ,the advantages of the eight-cylinder engine over the six and twelve1 briefly stated1 are3 lower weight per horse-power1 shorter length1 simpler and stiffer crank-shaft1 cam-shaft and crank-case1 and simpler and more direct manifold arrangement4 ,as to torque1 the eight is superior to the six1 and yet in practice not enough inferior to the twelve to warrant the addition of four more cylinders4 ,it must1 however1 be recognized that the eight is subject to the action of inherent unbalanced inertia couples1 which set up horizontal vibrations1 impossible of total elimination4 ,these vibrations are functions of the reciprocating weights1 which1 as already mentioned1 are cut down to the minimum4 ,vibrations due to the elasticity of crank-case1 crank-shaft1 etc41 can be and are reduced in the ,thomas engine to minor quantities by ample webbing of the crank-case and judicious use of metal elsewhere4 ,all things considered1 there is actually so little difference to be discerned between the balance of a properly designed eight-cylinder engine and that of a six or twelve as to make a discussion of the pros and cons more one of theory than of practice4 ,the main criticisms of the ,l head cylinder engine are that it is less efficient and heavier4 ,this is granted1 as it relates to cylinders alone4 ,more thorough investigation1 however1 based on the main desideratum1 weight-power ratio1 leads us to other conclusions1 particularly with reference to high speed engines4 ,the valve gear must not be forgotten4 ,a cylinder cannot be taken completely away from its component parts and judged1 as to its weight value1 by itself alone4 ,a part away from the whole becomes an item unimportant in comparison with the whole4 ,the valve gear of a high speed engine is a too often overlooked feature4 ,the stamp of approval has been made by high speed automobile practice upon the overhead cam-shaft drive1 with valves in the cylinder head operated direct from the cam-shaft or by means of valve lifters or short rockers4 ,the overhead cam-shaft mechanism applied to an eight-cylinder engine calls for two separate cam-shafts carried above and supported by the cylinders in an oil-tight housing1 and driven by a series of spur gears or bevels from the crank-shaft4 ,it is patent that this valve gearing is heavy and complicated in comparison with the simple moving valve units of the ,l head engine1 which are operated from one single cam-shaft1 housed rigidly in the crank-case4 ,the inherently lower volumetric efficiency of the ,l head engine is largely overcome by the use of a properly designed head1 large valves and ample gas passages4 ,again1 the customary use of a dual ignition system gives to the ,l head a relatively better opportunity for the advantageous placing of spark-plugs1 in order that better flame propagation and complete combustion may be secured4 ,illustration3 ,fig4 #bcc4--;,end ,view of ,thomas-,morse #aej ,horse-,power ,aluminum ,cylinder ,aviation ,motor ,having ,detachable ,cylinder ,heads4 ,the ,thomas ,model #hh engine is #d-a_/h inch bore and #e-a_/b inch stroke4 ,the cylinders and cylinder heads are of aluminum1 and as steel liners are used in the cylinders the pistons are also made of aluminum4 ,this engine is actually lighter than the earlier model of less power4 ,it weighs but #ebe pounds1 with self-starter4 ,the general features of design can be readily ascertained by study of the illustrations3 ,fig4 #bcc1 which shows an end view2 ,fig4 #bcd1 which is a side view1 and ,fig4 #bce1 which outlines the reduction gear-case and the propeller shaft supporting bearings4 ,illustration3 ,fig4 #bcd4--,side ,view of ,thomas-,morse ,high ,speed #aej ,horse-,power ,aviation ,motor with ,geared ,down ,propeller ,drive4 ,,sixteen-,,valve ,,duesenberg ,,engine ,illustration3 ,fig4 #bce4--,the ,reduction ,gear-,case of ,thomas-,morse #aej ,horse-,power ,aviation ,motor1 ,showing ,ball ,bearing and ,propeller ,drive ,shaft ,gear4 ,this engine is a four-cylinder1 #d-c_/d x #g1 #abe horse-power at #b1ajj ,r4 ,p4 ,m4 of the crank-shaft and #a1baj ,r4 ,p4 ,m4 of the propeller4 ,motors are sold on above rating2 actual power tests prove this motor capable of developing #adj horse-power at #b1ajj ,r4 ,p4 ,m4 of the motor4 ,the exact weight with magneto1 carburetor1 gear reduction and propeller hub1 as illustrated1 #eji pounds2 without gear reduction1 #dcf pounds4 ,this motor has been produced as a power plant weighing #c4e pounds per horse-power1 yet nothing has been sacrificed in rigidity and strength4 ,at its normal speed it develops #a horse-power for every #c4e cubic inches piston displacement4 ,cylinders are semi-steel1 with aluminum plates enclosing water jackets4 ,pistons specially ribbed and made of ,magnalite aluminum compound4 ,piston rings are special ,duesenberg design1 being three-piece rings4 ,valves are tungsten steel1 #a-ae_/af inlets and #b exhausts1 two of each to each cylinder4 ,arranged horizontally in the head1 allowing very thorough water-jacketing4 ,inlet valves in cages4 ,exhaust valves1 seating directly in the cylinder head1 are removable through the inlet valve holes4 ,valve stems lubricated by splash in the valve action covers4 ,valve rocker arms forged with cap screw and nut at upper end to adjust clearance4 ,entirely enclosed by aluminum housing1 as is entire valve mechanism4 ,connecting rods are tubular1 chrome nickel steel1 light and strong4 ,crank-shaft is one-piece forging1 hollow bored1 #b-a_/b-;inch diameter at main bearings4 ,connecting rod bearings1 #b-a_/d-;inch diameter1 #c inches long4 ,front main bearing1 #c-a_/b inches long2 intermediate main bearing1 #c-a_/b inches long2 rear main bearing1 #d inches long4 ,crank-case of aluminum1 barrel type1 oil pan on bottom removable4 ,hand hole plates on both sides4 ,strongly webbed4 ,the oiling system of this sixteen-valve ,duesenberg motor is one of its vital features4 ,an oil pump located in the base and submerged in oil forces oil through cored passages to the three main bearings1 then through tubes under each connecting rod into which the rod dips4 ,the oil is thrown off from these and lubricates every part of the motor4 ,this constitutes the main oiling system2 it is supplemented by a splash system1 there being a trough under each connecting rod into which the rod slips4 ,the oil is returned to the main supply sump by gravity1 where it is strained and re-used4 ,either system is in itself sufficient to operate the motor4 ,a pressure gauge is mounted for observation on a convenient part of the system4 ,a pressure of approximately #be pounds is maintained by the pressure system1 which insures efficient lubrication at all speeds of the motor4 ,the troughs under the connecting rods are so constructed that no matter what the angle of flight may be1 oil is retained in each individual trough so that each connecting rod can dip up its supply of oil at each revolution4 ,,aeromarine ,,six-,,cylinder ,,vertical ,,motor ,illustration3 ,fig4 #bcf4--,the ,six-,cylinder ,aeromarine ,engine4 ,these motors are four-stroke cycle1 six-cylinder vertical type1 with cylinder #d-e_/af bore by #e-a_/h stroke4 ,the general appearance of this motor is shown in illustration at ,fig4 #bcf4 ,this engine is rated at #he-ij horse-power4 ,all reciprocating and revolving parts of this motor are made of the highest grades of steel obtainable as are the studs1 nuts and bolts4 ,the upper and lower parts of crank-case are made of composition aluminum casting4 ,lower crank-case is made of high grade aluminum composition casting and is bolted directly to the upper half4 ,the oil reservoir in this lower half casting provides sufficient oil capacity for five hours' continuous running at full power4 ,increased capacity can be provided if needed to meet greater endurance requirements4 ,oil is forced under pressure to all bearings by means of high-pressured duplex-geared pumps4 ,one side of this pump delivers oil under pressure to all the bearings1 while the other side draws the oil from the splash case and delivers it to the main sump4 ,the oil reservoir is entirely separate from the crank-case chamber4 ,under no circumstances will oil flood the cylinder1 and the oiling system is not affected in any way by any angle of flight or position of motor4 ,an oil pressure gauge is placed on instrument board of machine1 which gives at all times the pressure in oil system1 and a sight glass at lower half of case indicates the amount of oil contained4 ,the oil pump is external on magneto end of motor1 and is very accessible4 ,an external oil strainer is provided1 which is removable in a few minutes' time without the loss of any oil4 ,all oil from reservoir to the motor passes through this strainer4 ,pressure gauge feed is also attached and can be piped to any part of machine desired4 ,the cylinders are made of high-grade castings and are machined and ground accurately to size4 ,cylinders are bolted to crank-case with chrome nickel steel studs and nuts which securely lock cylinder to upper half of crank-case4 ,the main retaining cylinder studs go through crank-case and support crank-shaft bearings so that crank-shaft and cylinders are tied together as one unit4 ,water jackets are of copper1 #a_/af thick1 electrically deposited4 ,this makes a non-corrosive metal4 ,cooling is furnished by a centrifugal pump1 which delivers #be gallons per minute at #a1djj ,r4 ,p4 ,m4 ,pistons are made cast iron1 accurately machined and ground to exact dimensions1 which are carefully balanced4 ,piston rings are semi-steel rings of ,aeromarine special design4 ,connecting rods are of chrome nickel steel1 ,h-section4 ,crank-shaft is made of chrome nickel steel1 machined all over1 and cut from solid billet1 and is accurately balanced through the medium of balance weights being forged integral with crank4 ,it is drilled for lightness and plugged for force feed lubrication4 ,there are seven main bearings to crank-shaft4 ,all bearings are of high-grade babbitt1 die cast1 and are interchangeable and easily replaced4 ,the main bearings of the crank-shaft are provided with a single groove to take oil under pressure from pressure tube which is cast integral with case4 ,connecting rod bearings are of the same type4 ,the gudgeon pin is hardened1 ground and secured in connecting rod1 and is allowed to work in piston4 ,cam-shaft is of steel1 with cams forged integral1 drilled for lightness and forced-feed lubrication1 and is case-hardened4 ,the bearings of cam-shaft are of bronze4 ,magneto1 two high-tension ,bosch ,d4 ,u4 #f4 ,the intake manifold for carburetors are aluminum castings and are so designed that each carburetor feeds three cylinders1 thereby insuring easy flow of vapor at all speeds4 ,weight1 #dbj pounds4 ,illustration3 ,fig4 #bcg4--,the ,wisconsin ,aviation ,engine1 at ,top1 as ,viewed from ,carburetor ,side4 ,below1 the ,exhaust ,side4 ,,wisconsin ,,aviation ,,engines ,illustration3 ,fig4 #bch4--;,dimensioned ,end ,elevation of ,wisconsin ,six ,motor4 ,the new six-cylinder ,wisconsin aviation engines1 one of which is shown at ,fig4 #bcg1 are of the vertical type1 with cylinders in pairs and valves in the head4 ,dimensioned drawings of the six-cylinder vertical type are given at ,figs4 #bch and #bci4 ,the cylinders are made of aluminum alloy castings1 are bored and machined and then fitted with hardened steel sleeves about #a_/af inch in thickness4 ,after these sleeves have been shrunk into the cylinders1 they are finished by grinding in place4 ,gray iron valve seats are cast into the cylinders4 ,the valve seats and cylinders1 as well as the valve ports1 are entirely surrounded by water jackets4 ,the valves set in the heads at an angle of #be deg4 from the vertical1 are made of tungsten steel and are provided with double springs1 the outer or main spring and the inner or auxiliary spring1 which is used as a precautionary measure to prevent a valve falling into the cylinder in remote case of a main spring breaking4 ,the cam-shaft is made of one solid forging1 case-hardened4 ,it is carried in an aluminum housing bolted to the top of the cylinders4 ,this housing is split horizontally1 the upper half carrying the chrome vanadium steel rocker levers4 ,the lower half has an oil return trough cast integral1 into which the excess oil overflows and then drains back to the crank-case4 ,small inspection plates are fitted over the cams and inner ends of the cam rocker levers4 ,the cam-shaft runs in bronze bearings and the drive is through vertical shaft and bevel gears4 ,illustration3 ,fig4 #bci4--;,dimensioned ,side ,elevation of ,wisconsin ,six ,motor4 ,the crank-case is made of aluminum1 the upper half carrying the bearings for the crank-shaft4 ,the lower half carries the oil sump in which all of the oil except that circulating through the system at the time is carried4 ,the crank-shaft is made of chrome vanadium steel of an elastic limit of #aae1jjj pounds4 ,the crank-pins and ends of the shaft are drilled for lightness and the cheeks are also drilled for oil circulation4 ,the crank-shaft runs in bronze-backed1 ,fahrig metal-lined bearings1 four in number4 ,a double thrust bearing is also provided1 so that the motor may be used either in a tractor or pusher type of machine4 ,outside of the thrust bearing an annular ball bearing is used to take the radial load of the propeller4 ,the propeller is mounted on a taper4 ,at the opposite end of the shaft a bevel gear is fitted which drives the cam-shaft1 through a vertical shaft1 and also drives the water and oil pumps and magnetos4 ,all gears are made of chrome vanadium steel1 heat-treated4 ,the connecting rods are tubular and machined from chrome vanadium steel forgings4 ,oil tubes are fitted to the rods which carry the oil up to the wrist-pins and pistons4 ,the rods complete with bushings weigh #e-a_/b pounds each4 ,the pistons are made of aluminum alloy and are very light and strong1 weighing only #b pounds #b ounces each4 ,two leak-proof rings are fitted to each piston4 ,the wrist-pins are hollow1 of hardened steel1 and are free to turn either in the piston or the rod4 ,a bronze bushing is fitted in the upper end of the rod1 but no bushing is fitted in the pistons1 the hardened steel wrist-pins making an excellent bearing in the aluminum alloy4 ,illustration3 ,fig4 #bdj4--,power1 ,torque and ,efficiency ,curves of ,wisconsin ,aviation ,motor4 ,the water circulation is by centrifugal pump1 which is mounted at the lower end of the vertical shaft4 ,the water is pumped through brass pipes to the lower end of the cylinder water jackets and leaves the upper end of the jackets just above the exhaust valves4 ,the lubricating system is one of the main features of the engines1 being designed to work with the motor at any angle4 ,the oil is carried in the sump1 from where it is taken by the oil circulating pump through a strainer and forced through a header1 extending the full length of the crank-case1 and distributed to the main bearings4 ,from the main bearings it is forced through the hollow crank-shaft to the connecting rod big ends and then through tubes on the rods to wrist-pins and pistons4 ,another lead takes oil from the main header to the cam-shaft bearings4 ,the oil forced out of the ends of the cam-shaft bearings fills pockets under the cams and in the cam rocker levers4 ,the excess flows back through pipes and through the train of gears to the crank-case4 ,a strainer is fitted at each end of the crank-case1 through which the oil is drawn by separate pumps and returned to the sump4 ,either one of these pumps is large enough to take care of all of the return oil1 so that the operation is perfect whether the motor is inclined up or down4 ,no splash is used in the crank-case1 the system being a full force feed4 ,an oil level indicator is provided1 showing the amount of oil in the sump at all times4 ,the oil pressure in these motors is carried at ten pounds1 a relief valve being fitted to hold the pressure constant4 ,illustration3 ,fig4 #bda4--,timing ,diagram1 ,wisconsin ,aviation ,engine4 ,ignition is by two ,bosch magnetos1 each on a separate set of plugs fired simultaneously on opposite sides of the cylinders4 ,should one magneto fail1 the other would still run the engine at only a slight loss in power4 ,the ,zenith double carburetor is used1 three cylinders being supplied by each carburetor4 ,this insures a higher volumetric efficiency1 which means more power1 as there is no overlapping of inlet valves whatever by this arrangement4 ,all parts of these motors are very accessible4 ,the water and oil pumps1 carburetors1 magnetos1 oil strainer or other parts can be removed without disturbing other parts4 ,the lower crank-case can be removed for inspection or adjustment of bearings1 as the crank-shaft and bearing caps are carried by the upper half4 ,the motor supporting lugs are also part of the upper crank-case4 ,the six-cylinder motor1 without carburetors or magnetos1 weighs #edg pounds4 ,with carburetor and magnetos1 the weight is #fjj pounds4 ,the weight of cooling water in the motor is #ch pounds4 ,the sump will carry #d gallons of oil1 or about #bh pounds4 ,a radiator can be furnished suitable for the motor1 weighing #ej pounds4 ,this radiator will hold #c gallons of water or about #be pounds4 ,the motor will drive a two-blade1 #h feet diameter by #f4be feet pitch ,paragon propeller #adjj revolutions per minute1 developing #adh horse-power4 ,the weight of this propeller is #db pounds4 ,this makes a total weight of motor1 complete with propeller1 radiator filled with water1 but without lubricating oil1 #gee pounds1 or about #e4a pounds per horse-power for complete power plant4 ,the fuel consumption is 4#e pound per horse-power per hour4 ,the lubricating oil consumption is 4#jage pound per horse-power per hour1 or a total of #b4f pounds per hour at #adjj revolutions per minute4 ,this would make the weight of fuel and oil1 per hour's run at full power at #adjj revolutions per minute1 #gf4f pounds4 ,,principal ,,dimensions ,following are the principal dimensions of the six-cylinder motor3 ,bore #e inches4 ,stroke #f-a_/b inches4 ,crank-shaft diameter throughout #b inches4 ,length of crank-pin and main bearings #c-a_/b inches4 ,diameter of valves #c inches 7#b-c_/d inches clear74 ,lift of valves #a_/b inch4 ,volume of compression space #bb per cent4 of total4 ,diameter of wrist-pins #a-c_/af inches4 ,firing order #a-d-b-f-c-e4 ,the horse-power developed at #abjj revolutions per minute is #acj1 at #acjj revolutions per minute #adj1 at #adjj revolutions per minute #adh4 #adjj is the maximum speed at which it is recommended to run these motors4 ,,twelve-,,cylinder ,,engine ,a twelve-cylinder ,v-type engine illustrated1 is also being built by this company1 similar in dimensions of cylinders to the six4 ,the principal differences being in the drive to cam-shaft1 which is through spur gears instead of bevel4 ,a hinged type of connecting rod is used which does not increase the length of the motor and1 at the same time1 this construction provides for ample bearings4 ,a double centrifugal water pump is provided for this motor1 so as to distribute the water uniformly to both sets of cylinders4 ,four magnetos are used1 two for each set of six cylinders4 ,the magnetos are very accessibly located on a bracket on the spur gear cover4 ,the carburetors are located on the outside of the motors1 where they are very accessible1 while the exhaust is in the center of the valley4 ,the crank-shaft on the twelve is #b-a_/b inches in diameter and the shaft is bored to reduce weight4 ,dimensioned drawings of the twelve-cylinder engine are given at ,figs4 #bdb and #bdc and should prove useful for purposes of comparison with other motors4 ,,hall-,,scott ,,aviation ,,engines ,the following specifications of the ,hall-,scott ,big ,four engines apply just as well to the six-cylinder vertical types which are practically the same in construction except for the structural changes necessary to accommodate the two extra cylinders4 ,cylinders are cast separately from a special mixture of semi-steel1 having cylinder head with valve seats integral4 ,special attention has been given to the design of the water jacket around the valves and head1 there being two inches of water space above same4 ,the cylinder is annealed1 rough machined1 then the inner cylinder wall and valve seats ground to mirror finish4 ,this adds to the durability of the cylinder1 and diminishes a great deal of the excess friction4 ,illustration3 ,fig4 #bdb4--;,dimensioned ,end ,view of ,wisconsin ,twelve-,cylinder ,airplane ,motor4 ,great care is taken in the casting and machining of these cylinders1 to have the bore and walls concentric with each other4 ,small ribs are cast between outer and inner walls to assist cooling as well as to transfer stresses direct from the explosion to hold-down bolts which run from steel main bearing caps to top of cylinders4 ,the cylinders are machined upon the sides so that when assembled on the crank-case with grooved hold-down washers tightened1 they form a solid block1 greatly assisting the rigidity of crank-case4 ,illustration3 ,fig4 #bdc4--;,dimensioned ,side ,elevation of ,wisconsin ,twelve-,cylinder ,airplane ,motor4 ,the connecting rods are very light1 being of the ,i beam type1 milled from a solid ,chrome nickel die forging4 ,the caps are held on by two #a_/b-bj thread ,chrome nickel through bolts4 ,the rods are first roughed out1 then annealed4 ,holes are drilled1 after which the rods are hardened and holes ground parallel with each other4 ,the piston end is fitted with a gun metal bushing1 while the crank-pin end carries two bronze serrated shells1 which are tinned and babbitted hot1 being broached to harden the babbitt4 ,between the cap and rod proper are placed laminated shims for adjustment4 ,crank-cases are cast of the best aluminum alloy1 hand scraped and sand blasted inside and out4 ,the lower oil case can be removed without breaking any connections1 so that the connecting rods and other working parts can readily be inspected4 ,an extremely large strainer and dirt trap is located in the center and lowest point of the case1 which is easily removed from the outside without disturbing the oil pump or any working parts4 ,a ,zenith carburetor is provided4 ,automatic valves and springs are absent1 making the adjustment simple and efficient4 ,this carburetor is not affected by altitude to any appreciable extent4 ,a ,hall-,scott device1 covered by ,u4 ,s4 ,patent ,no4 #a1jgh1iai1 allows the oil to be taken direct from the crank-case and run around the carburetor manifold1 which assists carburetion as well as reduces crank-case heat4 ,two waterproof four-cylinder ,splitdorf ,dixie magnetos are provided4 ,both magneto interruptors are connected to a rock shaft integral with the motor1 making outside connections unnecessary4 ,it is worthy of note that with this independent double magneto system1 one complete magneto can become inoperative1 and still the motor will run and continue to give good power4 ,the pistons as provided in the ,a-#g engines are cast from a mixture of steel and gray iron4 ,these are extremely light1 yet provided with six deep ribs under the arch head1 greatly aiding the cooling of the piston as well as strengthening it4 ,the piston pin bosses are located very low in order to keep the heat from the piston head away from the upper end of the connecting rod1 as well as to arrange them at the point where the piston fits the cylinder best4 ,three #a_/d rings are carried4 ,the pistons as provided in the ,a-#g;a engines are cast from aluminum alloy4 ,four #a_/d rings are carried4 ,in both piston types a large diameter1 heat treated1 ,chrome nickel steel wrist-pin is provided1 assembled in such a way as to assist the circular rib between the wrist-pin bosses to keep the piston from being distorted from the explosions4 ,the oiling system is known as the high pressure type1 oil being forced to the under side of the main bearings with from #e to #cj points pressure4 ,this system is not affected by extreme angles obtained in flying1 or whether the motor is used for push or pull machines4 ,a large gear pump is located in the lowest point of the oil sump1 and being submerged at all times with oil1 does away with troublesome stuffing boxes and check valves4 ,the oil is first drawn from the strainer in oil sump to the long jacket around the intake manifold1 then forced to the main distributor pipe in crank-case1 which leads to all main bearings4 ,a bi-pass1 located at one end of the distributor pipe1 can be regulated to provide any pressure required1 the surplus oil being returned to the case4 ,a special feature of this system is the dirt1 water and sediment trap1 located at the bottom of the oil sump4 ,this can be removed without disturbing or dismantling the oil pump or any oil pipes4 ,a small oil pressure gauge is provided1 which can be run to the aviator's instrument board4 ,this registers the oil pressure1 and also determines its circulation4 ,the cooling of this motor is accomplished by the oil as well as the water1 this being covered by patent ,no4 #a1jgh1iai4 ,this is accomplished by circulating the oil around a long intake manifold jacket2 the carburetion of gasoline cools this regardless of weather conditions4 ,crank-case heat is therefore kept at a minimum4 ,the uniform temperature of the cylinders is maintained by the use of ingenious internal outlet pipes1 running through the head of each of the six-cylinders1 rubber hose connections being used so that any one of the cylinders may be removed without disturbing the others4 ,slots are cut in these pipes so that cooler water is drawn directly around the exhaust valves4 ,extra large water jackets are provided upon the cylinders1 two inches of water space is left above the valves and cylinder head4 ,the water is circulated by a large centrifugal pump insuring ample circulation at all speeds4 ,the crank-shaft is of the five bearing type1 being machined from a special heat treated drop forging of the highest grade nickel steel4 ,the forging is first drilled1 then roughed out4 ,after this the shaft is straightened1 turned down to a grinding size1 then ground accurately to size4 ,the bearing surfaces are of extremely large size1 over-size1 considering general practice in the building of high speed engines of similar bore and stroke4 ,the crank-shaft bearings are #b in diameter by #a-ae_/af long1 excepting the rear main bearing1 which is #d-c_/h long1 and front main bearing1 which is #b-c_/af long4 ,steel oil scuppers are pinned and sweated onto the webs of the shaft1 which allows of properly oiling the connecting rod bearings4 ,two thrust bearings are installed on the propeller end of the shaft1 one for pull and the other for push4 ,the propeller is driven by the crank-shaft flange1 which is securely held in place upon the shaft by six keys4 ,these drive an outside propeller flange1 the propeller being clamped between them by six through bolts4 ,the flange is fitted to a long taper on crank-shaft4 ,this enables the propeller to be removed without disturbing the bolts4 ,timing gears and starting ratchets are bolted to a flange turned integral with shaft4 ,the cam-shaft is of the one piece type1 air pump eccentric1 and gear flange being integral4 ,it is made from a low carbon specially heat treated nickel forging1 is first roughed out and drilled entire length2 the cams are then formed1 after which it is case hardened and ground to size4 ,the cam-shaft bearings are extra long1 made from ,parson's ,white ,brass4 ,a small clutch is milled in gear end of shaft to drive revolution indicator4 ,the cam-shaft is enclosed in an aluminum housing bolted directly on top of all six cylinders1 being driven by a vertical shaft in connection with bevel gears4 ,this shaft1 in conjunction with rocker arms1 rollers and other working parts1 are oiled by forcing the oil into end of shaft1 using same as a distributor1 allowing the surplus supply to flow back into the crank-case through hollow vertical tube4 ,this supply oils the magneto and pump gears4 ,extremely large ,tungsten valves1 being one-half the cylinder diameter1 are seated in the cylinder heads4 ,large diameter oil tempered springs held in tool steel cups1 locked with a key1 are provided4 ,the ports are very large and short1 being designed to allow the gases to enter and exhaust with the least possible resistance4 ,these valves are operated by overhead one piece cam-shaft in connection with short ,chrome nickel rocker arms4 ,these arms have hardened tool steel rollers on cam end with hardened tool steel adjusting screws opposite4 ,this construction allows accurate valve timing at all speeds with least possible weight4 ,,censored ,,german ,,airplane ,,motors ,in a paper on ,aviation ,motors1 presented by ,e4 ,h4 ,sherbondy before the ,cleveland section of the ,s4 ,a4 ,e4 in ,june1 #aiag1 the ,mercedes and ,benz airplane motor is discussed in some detail and portions of the description follow4 ,illustration3 ,fig4 #bdd4--,side and ,end ,sectional ,views of ,four-,cylinder ,argus ,engine1 a ,german #ajj ,horse-,power ,design ,having ,bore and ,stroke of #adj mm41 or #e4fj inches1 and ,developing ,its ,power at #a1cfh ,r4,p4,m4 ,weight1 #cej ,pounds4 ,,mercedes ,,motor ,the #aej horse-power six-cylinder ,mercedes motor is #adj millimeters bore and #afj millimeters stroke4 ,the ,mercedes company started with smaller-sized cylinders1 namely #ajj millimeters bore and #adj millimeters stroke1 six-cylinders4 ,the principal features of the design are forged steel cylinders with forged steel elbows for gas passages1 pressed steel water jackets1 which when welded together forms the cylinder assembly1 the use of inclined overhead valves operated by means of an overhead cam-shaft through rocker arms which multiply with the motion of the cam4 ,by the use of steel cylinders1 not only is the weight greatly reduced1 but certain freedom from distortion through unequal sections1 leaks and cracks are entirely avoided4 ,the construction is necessarily very expensive4 ,it is certainly a sound job4 ,in the details of this construction there are a number of important things1 such as finished gas passages1 water-cooled valve guides and a very small mass of metal1 which is water-cooled1 surrounding the spark-plug4 ,of course1 it is necessary to use very high compression in aviation motors in order to secure high power and economy and owing to the fact that aviation motors are worked at nearly their maximum1 the heat flow through the cylinder1 piston1 and valves is many times higher than that encountered in automobile motors4 ,it has been found necessary to develop special types of pistons to carry the heat from the center of the head in order to prevent pre-ignition4 ,in the ,mercedes motor the pistons have a drop forged steel head which includes the piston boss and this head is screwed into a cast iron skirt which has been machined inside to secure uniform wall thickness4 ,,censored ,a ,piston ,displacement 7,cubic ,inches7 ,b ,weight of ,engine with ,carburetor and ,ignition ,c ,gas ,consumption ,maker's ,number,bore ,stroke ,name of 7,in- 7,in- and ,model ,cyl4 ches7 ches7 ,a ,h4,p4,r4,p4,m4 ,b ,c ---------------------------------------- --------------------------- ,aeromarine #f #d-a_/b #e-a_/h #ddi #he #adjj #ddj 444 ---------------------------------------- --------------------------- ,aeromarine #ab #d-e_/afe-a_/h 444 444 444 #gej 444 ,d-#ab ---------------------------------------- --------------------------- ,curtiss ,,ox #h #d #e #ejb4f #ij #adjj #cge 444 ---------------------------------------- --------------------------- ,curtiss #h #d-a_/d #e #efg4e #ajj #adjj #dbc 444 ,,oxx-#b ---------------------------------------- --------------------------- ,curtiss ,v-#b #h #e #g #aajj #bjj #adjj #fij 444 ---------------------------------------- --------------------------- ,,censored ---------------------------------------- --------------------------- ,general ,ve- #i #d4cc #e4i #hdh #ajj #abjj #bgbab gals_/hour at hicle ,gnome ,mono rated ,h4,p4 ---------------------------------------- --------------------------- ,gyro ,k #g #d-a_/b #f 444 #ij #abej #baeh gals_/hour at ,rotary1 ,le ,rhone ,type rated ,h4,p4 ---------------------------------------- --------------------------- ,gyro ,l #i #d-a_/b #f #hei #ajj #abjj #bheaj gals_/hour at ,rotary1 ,le ,rhone ,type rated ,h4,p4 ---------------------------------------- --------------------------- ,hall-,scott #d #e #g #eej #ij- #adjj #daj 444 ,a-#g #ajj ---------------------------------------- --------------------------- ,hall-,scott #f #e #g #hbe #abe #acjj #eib 444 ,a-#e ---------------------------------------- --------------------------- ,hispano- #h #d-e_/h #e #fgb #aed #aejj #dee 444 ,suiza ---------------------------------------- --------------------------- ,knox ,motors #ab #d-c_/d #g #aeee #cjj #ahjjadbeca4e gals_/hour ,co4 ---------------------------------------- --------------------------- ,maximotor #f #d-a_/b #e #dgg #he #afjj #cdj 444 ,a-#f ---------------------------------------- --------------------------- ,maximotor #f #e #f #gjf4h #aae #afjj #che 444 ,b-#f ---------------------------------------- --------------------------- ,maximotor #h #d-a_/b #e #fcf #aae #afjj #dbj 444 ,a-#h ---------------------------------------- --------------------------- ,packard #ab #ab #d #f #ijc #bbe #bajj #hjj 444 ---------------------------------------- --------------------------- ,sturtevant #h #d #e-a_/b #eeb4i #adj #bjjj #ehj 444 #e ---------------------------------------- --------------------------- ,sturtevant #h #d #e-a_/b 444 #adj #bjjj #eadac4ge gals_/hour #e-;,a ---------------------------------------- --------------------------- ,thomas #h #h #d #e-a_/b #eeb4i #ace #bjjj #fcj 444 lbs4 with self-starter ---------------------------------------- --------------------------- ,thomas #hh #h #d-a_/h #e-a_/b #eeb4i #aej #bajj #ebe 444 lbs4 with self-starter ---------------------------------------- --------------------------- ,wisconsin #f #e #f-a_/b #gfe4g #adj #achj #fcg 444 ---------------------------------------- --------------------------- ,wisconsin #ab #e #f-a_/b #aeca4d #bej #abjj 444 444 ---------------------------------------- --------------------------- ,the carburetor used on this #aej horse-power ,mercedes motor is precisely of the same type used on the ,twin ,six motor4 ,it has two venturi throats1 in the center of which is placed the gasoline spray nozzle of conventional type1 fixed size orifices1 immediately above which are placed two panel type throttles with side outlets4 ,an idling or primary nozzle is arranged to discharge above the top of the venturi throat4 ,the carburetor body is of cast aluminum and is water jacketed4 ,it is bolted directly to air passage passing through the top and bottom half of the crank-case which passes down through the oil reservoir4 ,the air before reaching the carburetor proper to some extent has cooled the oil in the crank chamber and has itself been heated to assist in the vaporization4 ,the inlet pipes themselves are copper4 ,all the passages between the venturi throat and the inlet valve have been carefully finished and polished4 ,the only abnormal thing in the design of this motor is the short connecting rod which is considerably less than twice the stroke and would be considered very bad practice in motor car engines4 ,a short connecting rod1 however1 possesses two very real virtues in that it cuts down height of the motor and the piston passes over the bottom dead center much more slowly than with a long rod4 ,illustration3 ,fig4 #bde4--,part ,sectional ,view of #ij ,horse-,power ,mercedes ,engine1 ,which is ,typical of the ,design of ,larger ,sizes4 ,other features of the design are a very stiff crank-case1 both halves of which are bolted together by means of long through bolts1 the crank-shaft main bearings are seated in the lower half of the case instead of in the usual caps and no provision is made for taking up the main bearings4 ,the ,mercedes company uses a plunger type of pump having mechanically operated piston valves and it is driven by means of worm gearing4 ,the overhead cam-shaft construction is extremely light4 ,the cam-shaft is mounted in a nearly cylindrical cast bronze case and is driven by means of bevel gears from the crank-shaft4 ,the vertical bevel gear shaft through which the drive is taken from the crank-shaft to the cam-shaft operates at one and one-half times the crank-shaft speeds and the reduction to the half-time cam-shaft is secured through a pair of bevels4 ,on this vertical shaft there is mounted the water pump and a bevel gear for driving two magnetos4 ,the water pump mounted on this shaft tends to steady the drive and avoid vibration in the gearing4 ,the cylinder sizes of six-cylinder aviation motors which have been built by ,mercedes are ,bore ,stroke ,horse-power #aje mm4 #adj mm4 #ajj #abj mm4 #adj mm4 #ace #adj mm4 #aej mm4 #aej #adj mm4 #afj mm4 #afj ,the largest of these motors has recently had its horse-power increased to #agf at #adej ,r4 ,p4 ,m4 ,this general design of motor has been the foundation for a great many other aviation motor designs1 some of which have proved very successful but none of which is equal to the original4 ,among the motors which follow more or less closely the scheme of design and arrangement are the ,hall-,scott1 the ,wisconsin motor1 the ,renault water-cooled1 the ,packard1 the ,christofferson and the ,rolls-,royce4 ,each of these motors show considerable variation in detail4 ,the ,rolls-,royce and ,renault are the only ones who have used the steel cylinder with the steel jacket4 ,the ,wisconsin motor uses an aluminum cylinder with a hardened steel liner and cast-iron valve seats4 ,the ,christofferson has somewhat similar design to the ,wisconsin with the exception that the valve seats are threaded into the aluminum jacket and the cylinder head has a blank end which is secured to the aluminum casting by means of the valve seat pieces4 ,the ,rolls-,royce motors show small differences in details of design in cylinder head and cam-shaft housing from the ,mercedes on which it has taken out patents1 not only abroad but in this country4 ,,the ,,benz ,,motor ,in the ,kaiser prize contest for aviation motors a four-cylinder ,benz motor of #acj by #ahj mm4 won first prize1 developing #ajc ,b4 ,h4 ,p4 at #abij ,r4 ,p4 ,m4 ,the fuel consumption was #baj grams per horse-power hour4 ,total weight of the motor was #aec kilograms4 ,the oil consumption was 4#jb of a kilogram per horse-power hour4 ,this motor was afterward expanded into a six-cylinder design and three different sizes were built4 ,the accompanying table gives some of the details of weight1 horse-power1 etc4 ,motor type ,b ,,fd ,,ff ,rated horse-power #he #ajj #aej ,horse-power at #abej r4p4m #hh #ajh #aej ,horse-power at #acej r4p4m #ie #aae #afj ,bore in millimeters #ajf #aaf #acj ,stroke in millimeters #aej #afj #ahj ,offset of the cylinders in millimeters #ah #bj #bj ,rate of gasoline consumption in grams #bdj #bcj #bbe ,oil consumption in grams per b4h4p4 hour #aj #aj #aj ,oil capacity in kilograms #cf #d #d-a_/b ,water capacity in litres #e-a_/b #g-a_/b #i-a_/b ,the weight with water and oil but with two magnetos1 fuel feeder and air pump in kilograms #agj #bjj #bde ,the weight of motors1 including the water pump1 two magnetos1 double ignition1 etc4 #afj #aij #bcj ,the weight of the exhaust pipe1 complete in kilograms #d #d4h #e-a_/b ,the weight of the propeller hub in kilograms4 #c-a_/b #d #d ,the ,benz cylinder is a simple1 straightforward design and a very reliable construction and not particularly difficult to manufacture4 ,the cylinder is cast of iron without a water jacket but including #de degrees angle elbows to the valve ports4 ,the cylinders are machined wherever possible and at other points have been hand filed and scraped1 after which a jacket1 which is pressed in two halves1 is gas welded by means of short pipes welded on to the jacket4 ,the bottom and the top of the cylinders become water galleries1 and by this means separate water pipes with their attendant weight and complication are eliminated4 ,rubber rings held in aluminum clamps serve to connect the cylinders together4 ,the whole construction turns out very neat and light4 ,the cylinder walls are #d mm4 or #c_/af thick and the combustion chamber is of cylindrical pancake form and is #adj mm4 or #e4fj inch in diameter4 ,the valve seats are #fh mm4 in diameter and the valve port is #fb mm4 in diameter4 ,the passage joining the port is #eg mm4 in diameter4 ,in order to insert the valves into the cylinder the valve stem is made with two diameters and the valve has to be cocked to insert it in the guide1 which has a bronze bushing at its upper end to compensate for the smaller valve stem diameter4 ,the valve stem is #ad mm4 or #i_/af in diameter and is reduced at its upper portion to #i-a_/b mm4 ,the valves are operated through a push rod and rocker arm construction1 which is #g_/af and exceedingly light4 ,rocker arm supports are steel studs with enlarged heads to take a double row ball bearing4 ,a roller is mounted at one end of the rocker arm to impinge on the end of the valve stem1 and the rocker arm has an adjustable globe stud at the other end4 ,the push rods are light steel tubes with a wall thickness of #j4ge mm4 and have a hardened steel cup at their upper end to engage the rocker arm globe stud and a hardened steel globe at their lower end to socket in the roller plunger4 ,the ,benz cam-shaft has a diameter of #bf mm4 and is bored straight through #ah mm4 and there is a spiral gear made integrally with the shaft in about the center of its length for driving the oil pump gear4 ,the cam faces are #aj mm4 wide4 ,there is also1 in addition to the intake and exhaust cams1 a set of half compression cams4 ,the shaft is moved longitudinally in its bearings by means of an eccentric to put these cams into action4 ,at the fore end of the shaft is a driving gear flange which is very small in diameter and very thin4 ,the flange is #fh mm4 in diameter and #d mm4 thick and is tapped to take #f mm4 bolts4 ,the total length of cam-shaft is #ajch mm41 and it becomes a regular gun boring job to drill a hole of this length4 ,the cam-shaft gear is #adj mm4 or #e-a_/b inches outside diameter4 ,it has fifty-four teeth and the gear face is #ae mm4 or #ai_/cb4 ,the flange and web have an average thickness of #d mm4 or #e_/cb and the web is drilled full of holes interposed between the spur gear mounted on the cam-shaft and the cam-shaft gear4 ,there is a gear which serves to drive the magnetos and tachometer1 also the air pump4 ,the shaft is made integrally with this gear and has an eccentric portion against which the air pump roll plunger impinges4 ,the seven-bearing crank-shaft is finished all over in a beautiful manner1 and the shaft out of the particular motor we have shows no signs of wear whatever4 ,the crank-pins are #ee mm4 in diameter and #fi mm4 long4 ,through both the crank-pin and main bearings there is drilled a #bh mm4 hole1 and the crank cheeks are plugged with solder4 ,the crank cheeks are also built to convey the lubricant to the crank-pins4 ,at the fore end of the crank cheek there is pressed on a spur driving gear4 ,there is screwed on to the front end of the shaft a piece which forms a bevel water pump driving gear and the starting dog4 ,at the rear end of the shaft very close to the propeller hub mounting there is a double thrust bearing to take the propeller thrust4 ,long1 shouldered studs are screwed into the top half of the crank-case portion of the case and pass clean through the bottom half of the case4 ,the case is very stiff and well ribbed4 ,the three center bearing diaphragms have double walls4 ,the center one serves as a duct through which water pipe passes1 and those on either side of the center form the carburetor intake air passages and are enlarged in section at one side to take the carburetor barrel throttle4 ,the pistons are of cast iron and carry three concentric rings #a_/d inch wide on their upper end1 which are pinned at the joint4 ,the top of the piston forms the frustum of the cone and the pistons are #aaj mm4 in length4 ,the lower portion of the skirt is machined inside and has a wall thickness of #a mm4 ,riveted to the piston head is a conical diaphragm which contacts with the piston pin when in place and serves to carry the heat off the center of the piston4 ,the oil pump assembly comprises a pair of plunger pumps which draw oil from a separate outside pump1 and constructed integrally with it is a gear pump which delivers the oil under about #fj pound pressure through a set of copper pipes in the base to the main bearings4 ,the plunger oil pump shows great refinement of detail4 ,a worm wheel and two eccentrics are machined up out of one piece and serve to operate the plungers4 ,illustration3 ,fig4 #bdf4--,part ,sectional ,side ,view and ,sectional ,end ,view of ,benz #afj ,horse-,power ,aviation ,engine4 ,some interesting details of the #afj horse-power ,benz motor1 which is shown at ,fig4 #bdf1 are reproduced from the ,aerial ,age ,weekly1 and show how carefully the design has been considered4 ,maximum horse-power1 #afg4e ,b4 ,h4 ,p4 ,speed at maximum horse-power1 #a1ejj ,r4 ,p4 ,m4 ,piston speed at maximum horse-power1 #a1ggj ft4 per minute4 ,normal horse-power1 #afj ,b4 ,h4 ,p4 ,speed at normal horse-power1 #a1djj ,r4 ,p4 ,m4 ,piston speed at normal horse-power1 #a1fef ft4 per minute4 ,brake mean pressure at maximum horse-power1 #aja4b pound per square inch4 ,brake mean pressure at normal horse-power1 #ajc4d pound per square inch4 ,specific power cubic inch swept volume per ,b4 ,h4 ,p41 #e4df cubic inch2 #afj ,b4 ,h4 ,p4 ,weight of piston1 complete with gudgeon pin1 rings1 etc41 #e4j pound4 ,weight of connecting rod1 complete with bearings1 #d4ii pound2 #a4h pound reciprocating4 ,weight of reciprocating parts per cylinder1 #f4h pound4 ,weight of reciprocating parts per square inch of piston area1 #j4cc pound4 ,outside diameter of inlet valve1 #fh mm42 #b4fh inches4 ,diameter of inlet valve port 7d71 #fa4e mm42 #b4db inches4 ,maximum lift of inlet valve 7h71 #aa mm42 #j4ddc inch4 ,area of inlet valve opening 7pi d h71 #ba4be square cm42 #c4bi square inches4 ,inlet valve opens1 degrees on crank1 top dead center4 ,inlet valve closes1 degrees on crank1 #fj deg4 late2 #ce mm4 late4 ,outside diameter of exhaust valve1 #fh mm42 #b4fh inches4 ,diameter of exhaust valve port 7d71 #fa4e mm42 #b4db inches4 ,maximum lift of exhaust valve 7h7 #aa mm42 #j4dcc inch4 ,area of exhaust valve opening 7pi d h71 #ba4be square cm42 #c4bi square inches4 ,exhaust valve opens1 degrees on crank1 #fj deg4 early2 #ce mm4 early4 ,exhaust valve closes1 degrees on crank1 #af-a_/b deg4 late2 #e mm4 late4 ,length of connecting rod between centers1 #cad mm42 #ab4cf inches4 ,ratio connecting rod to crank throw1 #c4di3a4 ,diameter of crank-shaft1 #ee mm4 outside1 #b4afe inches2 #bh mm4 inside1 #a4ajb inches4 ,diameter of crank-pin1 #ee mm4 outside1 #b4afe inches2 #bh mm4 inside1 #a4ajb inches4 ,diameter of gudgeon pin1 #cj mm4 outside1 #a4aha inches2 #ai mm4 inside1 #j4gjh inch4 ,diameter of cam-shaft1 #bf mm4 outside1 #a4jbc inches2 #ah mm4 inside1 #j4gjh inch4 ,number of crank-shaft bearings1 #g4 ,projected area of crank-pin bearings1 #cf4he square cm42 #e4gb square inches4 ,projected area of gudgeon pin bearings1 #bb4bj square cm42 #c4dd square inches4 ,firing sequence1 #a1 #e1 #c1 #f1 #b1 #d4 ,type of magnetos1 ,,zh#f ,bosch4 ,direction of rotation of magneto from driving end1 one clock1 one anti-clock4 ,magneto timing1 full advance1 #cj deg4 early 7#af mm4 early74 ,type of carburetors 7#b7 ,benz design4 ,fuel consumption per hour1 normal horse-power1 #j4eg pint4 ,normal speed of propeller1 engine speed1 #a1djj ,r4 ,p4 ,m4 ,,austro-,,daimler ,,engine ,one of the first very successful ,european flying engines which was developed in ,europe is the ,austro-,daimler1 which is shown in end section in a preceding chapter4 ,the first of these motors had four-cylinders1 #abj by #adj millimeters1 bore and stroke1 with cast iron cylinders1 overhead valves operated by means of a single rocker arm1 controlled by two cams and the valves were closed by a single leaf spring which oscillates with the rocker arm4 ,the cylinders are cast singly and have either copper or steel jackets applied to them4 ,the four-cylinder design was afterwards expanded to the six-cylinder design and still later a six-cylinder motor of #acj by #age millimeters was developed4 ,this motor uses an offset crank-shaft1 as does the ,benz motor1 and the effect of offset has been discussed earlier on in this treatise4 ,the ,benz motor also uses an offset cam-shaft which improves the valve operation and changes the valve lift diagram4 ,the lubrication also is different than any other aviation motor1 since individual high pressure metering pumps are used to deliver fresh oil only to the bearings and cylinders1 as was the custom in automobile practice some ten years ago4 ,,sunbeam ,,aviation ,,engines ,these very successful engines have been developed by ,louis ,coatalen4 ,at the opening of the war the largest sized ,coatalen motor was #bbe horse-power and was of the ,l-head type having a single cam-shaft for operating valves and was an evolution from the twelve-cylinder racing car which the ,sunbeam ,company had previously built4 ,since #aiad the ,sunbeam ,company have produced engines of six-1 eight-1 twelve- and eighteen-cylinders from #aej to #ejj horse-power with both iron and aluminum cylinders4 ,for the last two years all the motors have had overhead cam-shafts with a separate shaft for operating the intake and exhaust valves4 ,cam-shafts are connected through to the crank-shaft by means of a train of spur gears1 all of which are mounted on two double row ball bearings4 ,in the twin six1 #cej horse-power engine1 operating at #bajj ,r4 ,p4 ,m41 requires about #d horse-power to operate the cam-shafts4 ,this motor gives #cfb horse-power at #bajj revolutions and has a fuel consumption of #ea_/ajj of a pint per brake horse-power hour4 ,the cylinders are #aaj by #afj millimeters4 ,the same design has been expanded into an eighteen-cylinder which gives #ebe horse-power at #bajj turns4 ,there has also been developed a very successful eight-cylinder motor rated at #bbbj horse-power which has a bore and stroke of #abj by #acj millimeters1 weight #dej pounds4 ,this motor is an aluminum block construction with steel sleeves inserted4 ,three valves are operated1 one for the inlet and two for the exhaust4 ,one cam-shaft operates the three valves4 ,illustration3 ,fig4 #bdg4--;,at ,top1 the ,sunbeam ,overhead ,valve #agj ,horse-,power ,six-,cylinder ,engine4 ,below1 ,side ,view of ,sunbeam #cej ,horse-,power ,twelve-,cylinder ,vee ,engine4 ,the modern ,sunbeam engines operate with a mean effective pressure of #ace pounds with a compression ratio of #f to #a sea level4 ,the connecting rods are of the articulated type as in the ,renault motor and are very short4 ,the weight of these motors turns out at #b4f pounds per brake horse-power1 and they are able to go through a #ajj hour test without any trouble of any kind4 ,the lubricating system comprises a dry base and oil pump for drawing the oil off from the base1 whence it is delivered to the filter and cooling system4 ,it then is pumped by a separate high pressure gear pump through the entire motor4 ,in these larger ,european motors1 castor-oil is used largely for lubrication4 ,it is said that without the use of castor-oil it is impossible to hold full power for five hours4 ,coatalen favors aluminum cylinders rather than cast iron4 ,the series of views in ,figs4 #bdg to #bej inclusive1 illustrates the vertical1 narrow type of engine2 the ,v-form2 and the broad arrow type wherein three rows1 each of six-cylinders1 are set on a common crank-case4 ,in this water-cooled series the gasoline and oil consumption are notably low1 as is the weight per horse-power4 ,illustration3 ,fig4 #bdh4--,side ,view of ,eighteen-,cylinder ,sunbeam ,coatalen ,aircraft ,engine ,rated at #dge ,b4,h4,p4 ,illustration3 ,fig4 #bdi4--,sunbeam ,eighteen-,cylinder ,motor1 ,viewed from ,pump and ,magneto ,end4 ,in the eighteen-cylinder overhead valve ,sunbeam-,coatalen aircraft engine of #dge brake horse-power1 there are no fewer than half a dozen magnetos4 ,each magneto is inclosed4 ,two sparks are furnished to each cylinder from independent magnetos4 ,on this engine there are also no fewer than six carburetors4 ,shortness of crank-shaft1 and therefore of engine length1 and absence of vibration are achieved by the linking of the connecting-rods4 ,those concerned with three-cylinders in the broad arrow formation work on one crank-pin1 the outer rods being linked to the central master one4 ,in consequence of this arrangement1 the piston travel in the case of the central row of cylinders is #afj mm41 while the stroke of the pistons of the cylinders set on either side is in each case #afh mm4 ,inasmuch as each set of six-cylinders is completely balanced in itself1 this difference in stroke does not affect the balance of the engine as a whole4 ,the duplicate ignition scheme also applies to the twelve-cylinder #cej brake horse-power ,sunbeam-,coatalen overhead valve aircraft engine type4 ,it is distinguishable1 incidentally1 by the passage formed through the center of each induction pipe for the sparking plug in the center cylinder of each block of three4 ,in this1 as in the eighteen-cylinder and the six-cylinder types1 there are two cam-shafts for each set of cylinders4 ,these cam-shafts are lubricated by low pressure and are operated through a train of inclosed spur wheels at the magneto end of the machine4 ,the six-cylinder1 #agj brake horse-power vertical type employs the same general principles1 including the detail that each carburetor serves gas to a group of three-cylinders only4 ,it will be observed that this engine presents notably little head resistance1 being suitable for multi-engined aircraft4 ,illustration3 ,fig4 #bej4--,propeller ,end of ,sunbeam ,eighteen-,cylinder #dge ,b4,h4,p4 ,aviation ,engine4 ,,indicating ,,meters ,,for ,,auxiliary ,,systems ,illustration3 ,fig4 #bea4--,view of ,airplane ,cowl ,board1 ,showing the ,various ,navigating and ,indicating ,instruments to ,aid the ,aviator in ,flight4 ,the proper functioning of the power plant and the various groups comprising it may be readily ascertained at any time by the pilot because various indicating meters and pressure gauges are provided which are located on a dash or cowl board in front of the aviator1 as shown at ,fig4 #bea4 ,the speed indicator corresponds to the speedometer of an automobile and gives an indication of the speed the airplane is making1 which taken in conjunction with the clock will make it possible to determine the distance covered at a flight4 ,the altimeter1 which is an aneroid barometer1 outlines with fair accuracy the height above the ground at which a plane is flying4 ,these instruments are furnished to enable the aviator to navigate the airplane when in the air1 and if the machine is to be used for cross-country flying1 they may be supplemented by a compass and a drift set4 ,it will be evident that these are purely navigating instruments and only indicate the motor condition in an indirect manner4 ,the best way of keeping track of the motor action is to watch the tachometer or revolution counter which is driven from the engine by a flexible shaft4 ,this indicates directly the number of revolutions the engine is making per minute and1 of course1 any slowing up of the engine in normal flights indicates that something is not functioning as it should4 ,the tachometer operates on the same principle as the speed indicating device or speedometer used in automobiles except that the dial is calibrated to show revolutions per minute instead of miles per hour4 ,at the extreme right of the dash at ,fig4 #bea the spark advance and throttle control levers are placed4 ,these1 of course1 regulate the motor speed just as they do in an automobile4 ,next to the engine speed regulating levers is placed a push button cut-out switch to cut out the ignition and stop the motor4 ,three pressure gauges are placed in a line4 ,the one at the extreme right indicates the pressure of air on the fuel when a pressure feed system is used4 ,the middle one shows oil pressure1 while that nearest the center of the dash board is employed to show the air pressure available in the air starting system4 ,it will be evident that the character of the indicating instruments will vary with the design of the airplane4 ,if it was provided with an electrical starter instead of an air system electrical indicating instruments would have to be provided4 ,,compressed ,,air-,,starting ,,systems ,two forms of air-starting systems are in general use1 one in which the crank-shaft is turned by means of an air motor1 the other class where compressed air is admitted to the cylinders proper and the motor turned over because of the air pressure acting on the engine pistons4 ,a system known as the ,never-,miss utilizes a small double-cylinder air pump is driven from the engine by means of suitable gearing and supplies air to a substantial container located at some convenient point in the fuselage4 ,the air is piped from the container to a dash-control valve and from this member to a peculiar form of air motor mounted near the crank-shaft4 ,the air motor consists of a piston to which a rack is fastened which engages a gear mounted on the crank shaft provided with some form of ratchet clutch to permit it to revolve only in one direction1 and then only when the gear is turning faster than the engine crank-shaft4 ,the method of operation is extremely simple1 the dash-control valve admitting air from the supply tank to the top of the pump cylinder4 ,when in the position shown in cut the air pressure will force the piston and rack down and set the engine in motion4 ,a variety of air motors are used and in some the pump and motor may be the same device1 means being provided to change the pump to an air motor when the engine is to be turned over4 ,the ,christensen air starting system is shown at ,figs4 #beb and #bec4 ,an air pump is driven by the engine1 and this supplies air to an air reservoir or container attached to the fuselage4 ,this container communicates with the top of an air distributor when a suitable control valve is open4 ,an air pressure gauge is provided to enable one to ascertain the air pressure available4 ,the top of each cylinder is provided with a check valve1 through which air can flow only in one direction1 i4e41 from the tank to the interior of the cylinder4 ,under explosive pressure these check valves close4 ,the function of the distributor is practically the same as that of an ignition timer1 its purpose being to distribute the air to the cylinders of the engine only in the proper firing order4 ,all the while that the engine is running and the car is in motion the air pump is functioning1 unless thrown out of action by an easily manipulated automatic control4 ,when it is desired to start the engine a starting valve is opened which permits the air to flow to the top of the distributor1 and then through a pipe to the check valve on top of the cylinder about to explode4 ,as the air is going through under considerable pressure it will move the piston down just as the explosion would1 and start the engine rotating4 ,the inside of the distributor rotates and directs a charge of air to the cylinder next to fire4 ,in this way the engine is given a number of revolutions1 and finally a charge of gas will be ignited and the engine start off on its cycle of operation4 ,to make starting positive and easier some gasoline is injected in with the air so an inflammable mixture is present in the cylinders instead of air only4 ,this ignites easily and the engine starts off sooner than would otherwise be the case4 ,the air pressure required varies from #abe to #bej pounds per square inch1 depending upon the size and type of the engine to be set in motion4 ,illustration3 ,fig4 #beb4--,parts of ,christensen ,air ,starting ,system ,shown at ,a1 and ,application of ,piping and ,check ,valves to ,cylinders of ,thomas-,morse ,aeromotor ,outlined at ,b4 ,illustration3 ,fig4 #bec4--;,diagrams ,showing ,installation of ,air ,starting ,system on ,thomas-,morse ,aviation ,motor4 ,,electric ,,starting ,,systems ,starters utilizing electric motors to turn over the engine have been recently developed1 and when properly made and maintained in an efficient condition they answer all the requirements of an ideal starting device4 ,the capacity is very high1 as the motor may draw current from a storage battery and keep the engine turning over for considerable time on a charge4 ,the objection against their use is that it requires considerable complicated and costly apparatus which is difficult to understand and which requires the services of an expert electrician to repair should it get out of order1 though if battery ignition is used the generator takes the place of the usual ignition magneto4 ,in the ,delco system the electric current is generated by a combined motor-generator permanently geared to the engine4 ,when the motor is running it turns the armature and the motor generator is acting as a dynamo1 only supplying current to a storage battery4 ,on account of the varying speeds of the generator1 which are due to the fluctuation in engine speed1 some form of automatic switch which will disconnect the generator from the battery at such times that the motor speed is not sufficiently high to generate a current stronger than that delivered by the battery is needed4 ,these automatic switches are the only delicate part of the entire apparatus1 and while they require very delicate adjustment they seem to perform very satisfactorily in practice4 ,when it is desired to start the engine an electrical connection is established between the storage battery and the motor-generator unit1 and this acts as a motor and turns the engine over by suitable gearing which engages the gear teeth cut into a special gear or disc attached to the engine crank-shaft4 ,when the motor-generator furnishes current for ignition as well as for starting the motor1 the fact that the current can be used for this work as well as starting justifies to a certain extent the rather complicated mechanism which forms a complete starting and ignition system1 and which may also be used for lighting if necessary in night flying4 ,an electric generator and motor do not complete a self-starting system1 because some reservoir or container for electric current must be provided4 ,the current from the generator is usually stored in a storage battery from which it can be made to return to the motor or to the same armature that produced it4 ,the fundamental units of a self-starting system1 therefore1 are a generator to produce the electricity1 a storage battery to serve as a reservoir1 and an electric motor to rotate the motor crank-shaft4 ,generators are usually driven by enclosed gearing1 though silent chains are used where the center distance between the motor shaft and generator shaft is too great for the gears4 ,an electric starter may be directly connected to the gasoline engine1 as is the case where the combined motor-generator replaces the fly-wheel in an automobile engine4 ,the motor may also drive the engine by means of a silent chain or by direct gear reduction4 ,every electric starter must use a switch of some kind for starting purposes and most systems include an output regulator and a reverse current cut-out4 ,the output regulator is a simple device that regulates the strength of the generator current that is supplied the storage battery4 ,a reverse current cut-out is a form of check valve that prevents the storage battery from discharging through the generator4 ,brief mention is made of electric starting because such systems will undoubtedly be incorporated in some future airplane designs4 ,battery ignition is already being experimented with4 ,,battery ,,ignition ,,system ,,parts ,a battery ignition system in its simplest form consists of a current producer1 usually a set of dry cells or a storage battery1 an induction coil to transform the low tension current to one having sufficient strength to jump the air gap at the spark-plug1 an igniter member placed in the combustion chamber and a timer or mechanical switch operated by the engine so that the circuit will be closed only when it is desired to have a spark take place in the cylinders4 ,battery ignition systems may be of two forms1 those in which the battery current is stepped up or intensified to enable it to jump an air gap between the points of the spark plug1 these being called high tension systems and the low tension form 7never used on airplane motors7 in which the battery current is not intensified to a great degree and a spark produced in the cylinder by the action of a mechanical circuit breaker in the combustion chamber4 ,the low tension system is the simplest electrically but the more complex mechanically4 ,the high tension system has the fewest moving parts but numerous electrical devices4 ,at the present time all airplane engines use high tension ignition systems1 the magneto being the most popular at the present time4 ,the current distribution and timing devices used with modern battery systems are practically the same as similar parts of a magneto4 ,,index ,,page ,a ,action of ,four-cycle ,engine #ch ,action of ,le ,rhone ,rotary ,engine #ejc ,action of ,two-cycle ,engine #da ,action of ,vacuum ,feed ,system #aai ,actual ,duration of ,different ,functions #ic ,actual ,heat ,efficiency #fb ,adiabatic ,diagram #ea ,adiabatic ,law #ej ,adjustment of ,bearings #ddi ,adjustment of ,carburetors #aea ,aerial ,motors1 ,must be ,light #bj ,aerial ,motors1 ,operating ,conditions of #ai ,aerial ,motors1 ,requirements of #ai ,aeromarine ,six-cylinder ,engine #ebg ,aeronautics1 ,division in ,branches #ah ,aerostatics #ah ,air-cooled ,engine ,design #bbi ,air-cooling ,advantages #bca ,air-cooling1 ,direct ,method #bbh ,air-cooling ,disadvantages #bca ,air-cooling ,systems #bbc ,aircraft1 ,heavier ,than ,air #ag ,aircraft1 ,lighter ,than ,air #ah ,aircraft ,types1 ,brief ,consideration of #ag ,air ,needed to ,burn ,gasoline #aac ,airplane ,engine1 ,power ,needed #ba ,airplane ,engines1 ,overhauling #dab ,airplane ,engine1 ,how to ,time #bfi ,airplane ,engine ,lubrication #bji ,airplane1 ,how ,supported #ba ,airplane ,motors1 ,german #edc ,airplane ,motor ,types #bj ,airplane ,motors1 ,weight of #ba ,airplane ,power ,plant ,installation #cbd ,airplane ,types #ah ,airplanes1 ,horse-power ,used in #bf ,air ,pressure ,diminution1 ,with ,altitude #add ,altitude1 ,how it ,affects ,mixture #aec ,aluminum1 ,use in ,pistons #big ,american ,aviation ,engines1 ,statistics #edf ,anzani ,radial ,engine ,installation #cdd ,anzani ,six-cylinder ,star ,engine #dfe ,anzani ,six-cylinder ,water-cooled ,engine #dei ,anzani ,ten- and ,twenty-cylinder ,engines #dfh ,anzani ,three-cylinder ,engine #dei ,anzani ,three-cylinder ,y ,type #dfb ,argus ,engine ,construction #ede ,armature ,windings #afh ,atmospheric ,conditions1 ,compensating ,for #adc ,austro-,daimler ,engine #eeg ,aviatics #ah ,aviation ,engine1 ,aeromarine #ebg ,aviation ,engine1 ,anzani ,six-cylinder ,star #dfe ,aviation ,engine1 ,canton and ,unne #dfi ,aviation ,engine ,cooling #bai ,aviation ,engine1 ,curtiss #eai ,aviation ,engine ,cylinders #bcc ,aviation ,engine1 ,early ,gnome #dgb ,aviation ,engine1 ,german ,gnome ,type #die ,aviation ,engine1 ,gnome ,monosoupape #dhf ,aviation ,engine1 ,how ,to ,dismantle #dae ,aviation ,engine1 ,how to ,start #dfj ,aviation ,engine1 ,le ,rhone ,rotary #die ,aviation ,engine ,oiling #bah ,aviation ,engine ,parts1 ,functions of #hb ,aviation ,engine1 ,renault ,air-cooled #ejg ,aviation ,engine1 ,stand for ,supporting #dad ,aviation ,engine1 ,sturtevant #eae ,aviation ,engine1 ,thomas-,morse #eba ,aviation ,engine ,types #deg ,aviation ,engine1 ,wisconsin #eca ,aviation ,engines1 ,anzani ,six-cylinder ,water-cooled #dei ,aviation ,engines1 ,anzani ,ten- and ,twenty-cylinder #dfh ,aviation ,engines1 ,anzani ,three-cylinder #dei ,aviation ,engines1 ,anzani ,y ,type #dfb ,aviation ,engines1 ,argus #ede ,aviation ,engines1 ,austro-,daimler #eeg ,aviation ,engines1 ,benz #eea ,aviation ,engines1 ,four- and ,six-cylinder #hh ,aviation ,engines1 ,german #edc ,aviation ,engines1 ,hall-,scott #eci ,aviation ,engines1 ,hispano-,suiza #eab ,aviation ,engines1 ,mercedes #edc ,aviation ,engines1 ,overhauling #dab ,aviation ,engines1 ,principal ,parts of #hj ,aviation ,engines1 ,starting ,systems ,for #efg ,aviation ,engines1 ,sunbeam #eeh ,b ,balanced ,crank-shafts #cah ,ball-bearing ,crank-shafts #cai ,battery ,ignition ,systems #ega ,baverey ,compound ,nozzle #acg ,bearings1 ,adjustment of #ddi ,bearing ,alignment #dec ,bearing ,brasses1 ,fitting #dej ,bearing ,parallelism1 ,testing #dec ,bearing ,scrapers and ,their ,use #ddf ,benz ,aviation ,engines #eea ,benz ,engine ,statistics #eea ,berling ,magneto #agd ,berling ,magneto1 ,adjustment of #ahj ,berling ,magneto ,care #ahj ,berling ,magneto ,circuits #agf ,berling ,magneto1 ,setting #agh ,block ,castings #bcd ,blowing ,back #bfi ,bolts1 ,screwing ,down #deb ,bore and ,stroke ,ratio #bdj ,boyle's ,law #di ,brayton ,engine #dh ,breaker ,box1 ,adjustment of #ahj ,breast and ,hand ,drills #chg ,burning ,out ,carbon ,deposits #dba ,bushings1 ,cam-shaft1 ,wear in #def ,c ,calipers1 ,inside and ,outside #cih ,cam ,followers1 ,types of #bfj ,cams for ,valve ,actuation #bei ,cam-shaft ,bushings #def ,cam-shaft ,design #cac ,cam-shaft ,drive ,methods #bfa ,cam-shaft ,testing #dea ,cam-shafts and ,timing ,gears #def ,canton and ,unne ,engine #dfi ,carbon1 ,burning out with ,oxygen #dba ,carbon ,deposits1 ,cause of #dah ,carbon ,removal #dai ,carbon ,scrapers1 ,how ,used #dbj ,carburetion ,principles #aab ,carburetion ,system ,troubles #cee ,carburetor1 ,claudel #abg ,carburetor1 ,compound ,nozzle ,zenith #ace ,carburetor1 ,concentric ,float and ,jet ,type #abe ,carburetor1 ,duplex ,zenith #ach ,carburetor1 ,duplex ,zenith1 ,trouble in #ceg ,carburetor ,installation1 ,in ,airplanes #adh ,carburetor1 ,le ,rhone #eja ,carburetor1 ,master ,multiple ,jet #acc ,carburetor1 ,schebler #abe ,carburetor ,troubles1 ,how to ,locate #ced ,carburetor1 ,two ,stage #aca ,carburetor1 ,what it ,should ,do #aad ,carburetors1 ,float ,feed #abb ,carburetors1 ,multiple ,nozzle #acj ,carburetors1 ,notes on ,adjustment #aea ,carburetors1 ,reversing ,position of #adi ,carburetors1 ,spraying #abj ,care of ,dixie ,magneto #ahh ,castor ,oil1 for ,cylinder ,lubrication #bje ,castor ,oil1 ,why ,used ,in ,gnome ,engines #baa ,center ,gauge #djc ,chisels1 ,forms of #chd ,christensen ,air ,starting ,system #efg ,circuits1 ,magnetic #afa ,classification of ,engines #deh ,claudel ,carburetor #abg ,cleaning ,distributor #ahj ,clearances ,between ,valve ,stem and ,actuators #bfa ,combustion ,chamber ,design #bci ,combustion ,chambers1 ,spherical #gf ,common ,tools1 ,outfit of #cgh ,comparing ,two-cycle and ,four-cycle ,types #dd ,compound ,cam ,followers #bfj ,compound ,piston ,rings #cja ,compressed ,air ,starting ,system #efe ,compression1 ,factors ,limiting #fi ,compression1 in ,explosive ,motors1 ,value of #fh ,compression ,pressures1 ,chart for #gb ,compression ,temperature #ga ,computations for ,horse-power ,needed #be ,computations for ,temperature #eb ,concentric ,piston ,ring #bii ,concentric ,valves #bee ,connecting ,rod ,alignment1 ,testing #ded ,connecting ,rod1 ,conventional #cjh ,connecting ,rod ,forms #cje ,connecting ,rod1 ,gnome ,engine #cje ,connecting ,rods1 ,fitting #ddi ,connecting ,rods for ,vee ,engines #caj ,connecting ,rods1 ,le ,rhone #dih ,connecting ,rods1 ,master #caj ,constant ,level ,splash ,system #bae ,construction of ,dixie ,magneto #ahf ,construction of ,pistons #bhh ,conversion of ,heat to ,power #eh ,cooling by ,air #bbc ,cooling by ,positive ,water ,circulation #bbd ,cooling1 ,heat ,loss in #ff ,cooling ,system ,defects #ceh ,cooling ,systems ,used #bbc ,cooling ,systems1 ,why ,needed #bai ,cotter ,pin ,pliers #chd ,crank-case1 ,conventional #cbj ,crank-case ,forms #cbj ,crank-case1 ,gnome #cbc ,crank-shaft1 ,built ,up #cae ,crank-shaft ,construction #cae ,crank-shaft ,design #cae ,crank-shaft ,equalizer #ddi ,crank-shaft ,form #cae ,crank-shaft1 ,gnome ,engine #dhc ,crank-shafts1 ,balanced #cah ,crank-shafts1 ,ball ,bearing #cai ,cross ,level #djc ,crude ,petroleum1 ,distillates of #aaa ,curtiss ,aviation ,engines #eai ,curtiss ,engine ,installation #cbh ,curtiss ,engine ,repairing ,tools #djh ,cutting ,oil ,grooves #ddh ,cylinder ,blocks1 ,advantages of #bcg ,cylinder ,block1 ,duesenberg #bce ,cylinder ,castings1 ,individual #bcd ,cylinder ,construction #bcc ,cylinder ,faults and ,correction #daf ,cylinder ,form and ,crank-shaft ,design #bch ,cylinder ,head ,packings #dag ,cylinder ,head1 ,removable #bci ,cylinder1 ,i ,head ,form #bdh ,cylinder1 ,l ,head ,form #bdh ,cylinder ,oils #bjf ,cylinder ,placing #bj ,cylinder ,placing in ,v ,motor #ii ,cylinder ,retention1 ,gnome #dge ,cylinder1 ,t ,head ,form #bdh ,cylinders1 ,cast in ,blocks #bce ,cylinders1 ,odd ,number in ,rotary ,engines #dhb ,cylinders1 ,repairing ,scored #dbc ,cylinders1 ,valve ,location in #bde ,d ,defects in ,cylinders #dag ,defects in ,dry ,battery #cgc ,defects in ,fuel ,system #ced ,defects in ,induction ,coil #cgc ,defects in ,magneto #cgb ,defects in ,storage ,battery #cgb ,defects in ,timer #cgc ,defects in ,wiring and ,remedies #cgc ,die ,holder #cid ,dies for ,thread ,cutting #cie ,diesel ,motor ,cards #fg ,diesel ,system #add ,direct ,air ,cooling #bbh ,dirigible ,balloons #ah ,dismantling ,airplane ,engine #dae ,distillates of ,crude ,petroleum #aaa ,division of ,circle in ,degrees #bfh ,dixie ,ignition ,magneto #ahd ,dixie ,magneto1 ,care of #ahh ,draining ,oil ,from ,crank-case #bad ,drilling ,machines #chf ,drills1 ,types and ,use #chh ,driving ,cam-shaft1 ,methods of #bfb ,dry ,cell ,battery1 ,defects in #cgc ,duesenberg ,sixteen ,valve ,engine #ebe ,duesenberg ,valve ,action #bee ,duplex ,zenith ,carburetor #ach ,e ,early ,gnome ,motor1 ,construction of #dgb ,early ,ignition ,systems #aee ,early ,types of ,gas ,engine #bh ,early ,vaporizer ,forms #abj ,eccentric ,piston ,ring #bii ,economy1 ,factors ,governing #fd ,efficiency1 ,actual ,heat #fb ,efficiency1 ,maximum ,theoretical #fa ,efficiency1 ,mechanical #fb ,efficiency of ,internal ,combustion ,engine #fj ,efficiency1 ,various ,measures of #fa ,eight-cylinder ,engine #ie ,eight-cylinder ,timing ,diagram #bgf ,electricity and ,magnetism1 ,relation of #afb ,electrical ,ignition ,best #aef ,electric ,starting ,systems #efi ,engine1 ,advantages of ,v ,type #ie ,engine ,base ,construction #cai ,engine ,bearings1 ,adjusting #ddc ,engine ,bearings1 ,refitting #ddb ,engine ,bed ,timbers1 ,standard #ccj ,engine1 ,four-cycle1 ,action of #ch ,engine1 ,four-cycle1 ,piston ,movements in #dj ,engine ,functions1 ,duration of #ic ,engine ,ignition1 ,locating ,troubles #cec ,engine ,installation1 ,gnome #cdd ,engine ,installation1 ,anzani ,radial #cdd ,engine ,installation1 ,hall-,scott #ccb ,engine ,installation1 ,rotary #cdb ,engine ,operation1 ,sequence of #hd ,engine ,parts and ,functions #hj ,engine ,starts ,hard1 ,ignition ,troubles ,causing #cfi ,engine ,stoppage1 ,causes of #cdg ,engine ,temperatures #bba ,engine ,trouble ,charts #cfi ,engine ,troubles1 ,cooling #ceh ,engine ,troubles1 ,hints ,for ,locating #cde ,engine ,troubles1 ,ignition #cec ,engine ,troubles1 ,noisy ,operation #cei ,engine ,troubles1 ,oiling #ceg ,engine ,troubles ,summarized #cej ,engine1 ,two-cycle1 ,action of #da ,engines1 ,classification of #deh ,engines1 ,cylinder ,arrangement #ca-cb ,engines1 ,eight-cylinder ,v #ie ,engines1 ,four-cylinder ,forms #hh ,engines1 ,graphic ,comparison of #cc-cd-ce ,engines1 ,internal ,combustion1 ,types of #cj ,engines1 ,multiple ,cylinder1 ,power ,delivery in #ia ,engines1 ,multiple ,cylinder1 ,why ,best #hc ,engines1 ,rotary ,cylinder #ajg ,engines1 ,six-cylinder ,forms #hh ,engines1 ,twelve-cylinder #if ,equalizer1 ,crank-shaft #ddi ,exhaust ,closing #bgj ,exhaust ,valve ,design1 ,early ,gnome #dge ,exhaust ,valve ,opening #bgj ,explosive ,gases1 ,mixtures of #ef ,explosive ,motors1 ,inefficiency in #gd ,explosive ,motors1 ,why ,best #bg ,f ,factors ,governing ,economy #fd ,factors ,limiting ,compression #gj ,faults in ,ignition #ceb ,figuring ,horse-power ,needed #ba ,files1 ,use and ,care of #chc ,first ,law of ,gases #di ,fitting ,bearings ,by ,scraping #ddg ,fitting ,brasses #dej ,fitting ,connecting ,rods #ddi ,fitting ,main ,bearings #ddh ,fitting ,piston ,rings #dci ,float ,feed ,carburetor ,development #abd ,float ,feed ,carburetors #abb ,force ,feed ,oiling ,system #bah ,forked ,connecting ,rods #caj ,four-cycle ,engine1 ,action of #ch ,four-cycle ,engine1 ,why ,best #de ,fourteen-cylinder ,engine #dgd ,four ,valves ,per ,cylinder #bhd ,friction1 ,definition of #cjb ,fuel ,feed ,by ,gravity #aaf ,fuel ,feed by ,vacuum ,tank #aag ,fuel ,storage and ,supply #aaf ,fuel ,strainers1 ,types of #ada ,fuel ,strainers1 ,utility of #adj ,fuel ,system ,faults #ced ,fuel ,system ,installation1 ,hall-,scott #ccf ,fuel ,system1 ,gnome #dij ,fuel ,utilization ,chart #fb ,g ,gas ,engine1 ,beau de ,rocha's ,principles #ei ,gas ,engine ,development #bh ,gas ,engine1 ,early ,forms of #dh ,gas ,engine1 ,inventors of #bi ,gas ,engine1 ,theory of #dg ,gases1 ,compression of #di ,gases1 ,first ,law of #di ,gases1 ,second ,law of #ej ,gaskets1 ,how to ,use #deb ,gasoline1 ,air ,needed to ,burn #aac ,gas ,engines1 ,parts of #hj ,gas ,vacuum ,engine1 ,brown's #bh ,german ,airplane ,motors #edc ,german ,gnome ,type ,engine #die ,gnome ,aviation ,engine1 ,early ,form #dgb ,gnome ,crank-shaft #dhc ,gnome ,cylinder1 ,machining #dhi ,gnome ,cylinder ,retention #dge ,gnome ,engine1 ,fuel1 ,lubrication and ,ignition #dij ,gnome ,engine1 ,german ,type #die ,gnome ,engine ,installation #cdd ,gnome ,firing ,order #dhb ,gnome ,fourteen-cylinder1 ,engine #dgd ,gnome ,fourteen-cylinder ,engine ,details #dhj ,gnome ,monosoupape1 ,how to ,time #bgh ,gnome ,monosoupape ,type ,engine #dhf ,graphic ,comparison of ,engine ,types #cc-cd-ce ,graphic ,comparison1 ,two- and ,four-cycle #df ,gravity ,feed ,system #aaf ,grinding ,valves #dbi ,h ,hall-,scott ,aviation ,engines #eci ,hall-,scott ,engine ,installation #ccb ,hall-,scott ,engine1 ,preparations ,for ,starting #cda ,hall-,scott ,engine ,tools #daj ,hall-,scott ,lubrication ,system #baa ,hall-,scott ,statistic ,sheet #edd ,heat and ,its ,work #ed ,heat in ,gas ,engine ,cylinder #fi ,heat ,given to ,cooling ,water #gh ,heat ,loss1 ,causes of #gd ,heat ,loss in ,airplane ,engine #bba ,heat ,loss in ,wall ,cooling #fe ,high ,altitude1 ,how it ,affects ,power #add ,high ,tension ,magneto #agb ,hints ,for ,locating ,engine ,troubles #cde ,hints for ,starting ,engine #cfa ,hispano-,suiza ,model ,a ,engine #eab ,horse-power ,needed in ,airplane #ba ,horse-power ,needed1 ,how ,figured #bb ,how ,an ,engine is ,timed #bgg ,i ,ignition1 ,electric #aef ,ignition1 ,elements of #aeg ,ignition of ,gnome ,engine #dij ,ignition ,system1 ,battery #ega ,ignition ,systems1 ,early #aee ,ignition ,system ,faults #ceb ,ignition1 ,time of #bgc ,ignition1 ,two ,spark #aif ,i ,head ,cylinders #bdh ,improvements in ,gas ,engines #bi ,indicating ,meters1 ,engine ,speed #efc ,indicating ,meters1 ,oil and ,air ,pressure #efc ,indicator ,cards1 ,how ,to ,read #ff ,indicator ,cards1 ,value of #ff ,individual ,cylinder ,castings #bcd ,induction ,coil1 ,defects in #cgc ,inefficiency1 ,causes of #gd ,inlet ,valve ,closing #bgb ,inlet ,valve ,opening #bgj ,installation1 ,airplane ,engine #cbd ,installation1 ,curtiss ,,ox-#b ,engine #cbh ,installation1 ,hall-,scott ,engine #ccb ,installation of ,rotary ,engines #cdb ,intake ,manifold ,construction #adc ,intake ,manifold ,design #adb ,internal ,combustion ,engine1 ,efficiency of #fj1 #fb ,internal ,combustion ,engines1 ,main ,types of #cj ,inverted ,engine ,placing #cbe ,isothermal ,diagram #ea ,isothermal ,law #dh ,k ,keeping ,oil ,out of ,combustion ,chamber #cjc ,knight ,sleeve ,valves #bff ,l ,lag and ,lead1 ,explanation of #bfh ,lapping ,crank-pins #dde ,lead ,given ,exhaust ,valve #bgj ,leak ,proof ,piston ,rings #cja ,lenoir ,engine ,action #dh ,le ,rhone ,cams and ,valve ,actuation #ejj ,le ,rhone ,carburetor #eja ,le ,rhone ,connecting ,rod ,assembly1 ,distinctive #dih ,le ,rhone ,engine ,action #ejc ,le ,rhone ,rotary ,engine #die ,l ,head ,cylinders #bdh ,liquid ,fuels1 ,properties of #aaj ,locating ,carburetor ,troubles #ced ,locating ,engine ,troubles #cej ,locating ,ignition ,troubles #cec ,locating ,oiling ,troubles #ceg ,location of ,magneto ,trouble #aha ,losses in ,wall ,cooling #fe ,lost ,power and ,overheating1 ,summary of ,troubles ,causing #cfc ,lubricants1 ,derivation of #bjd ,lubricants1 ,requirements of #bjd ,lubricating ,system ,classification #bjh ,lubricating ,systems1 ,selection of #bjh ,lubrication ,by ,constant ,level ,splash ,system #bae ,lubrication ,by ,dry ,crank-case ,method #bah ,lubrication ,by ,force ,feed ,best #bah ,lubrication of ,magneto #ahj ,lubrication ,system1 ,gnome #dij ,lubrication ,system1 ,hall-,scott #baa ,lubrication ,system1 ,thomas-,morse #baj ,lubrication1 ,theory of #bjb ,lubrication1 ,why ,necessary #bja ,m ,magnetic ,circuits #afa ,magnetic ,influence ,defined #aeh ,magnetic ,lines of ,force #afa ,magnetic ,substances #aeh ,magnetism1 ,flow ,through ,armature #aff ,magnetism1 ,fundamentals of #aeg ,magnetism1 ,relation to ,electricity #afb ,magneto1 ,action of ,high ,tension #agc ,magneto ,armature ,windings #afh ,magneto1 ,basic ,principles of #afc ,magneto1 ,berling #agd ,magneto1 ,defects in #cgb ,magneto ,distributor1 ,cleaning #ahj ,magneto ,ignition ,systems #afi ,magneto ,ignition ,wiring #agi ,magneto ,interrupter1 ,adjustment of #ahj ,magneto1 ,low ,voltage #afh ,magneto1 ,lubrication of #ahj ,magneto ,maintenance #ahj ,magneto1 ,method of ,driving #age ,magneto ,parts and ,functions #afg ,magneto1 ,the ,dixie #ahd ,magneto ,timing #agi ,magneto1 ,timing ,dixie #ahh ,magneto1 ,transformer ,system #aga ,magneto ,trouble1 ,location of #aha ,magneto1 ,true ,high ,tension #agb ,magneto1 ,two ,spark ,dual #agg ,magnets1 ,forms of #afj ,magnets1 ,how ,produced #afb ,magnets1 ,properties of #aei ,main ,bearings1 ,fitting #ddh ,manifold1 ,intake #adc ,master ,multiple ,jet ,carburetor #acc ,master ,rod ,construction #caj ,maximum ,theoretical ,efficiency #fa ,meaning of ,piston ,speed #bda ,measures of ,efficiency #fa ,measuring ,tools #cig ,mechanical ,efficiency #fb ,mercedes ,aviation ,engine #edc ,metering ,pin ,carburetor1 ,stewart #abh ,micrometer ,caliper1 ,beading #dje ,micrometer ,calipers1 ,types and ,use #djd ,mixture1 ,effect of ,altitude on #aec ,mixture1 ,proportions of #aea ,mixture1 ,starvation of #adi ,monosoupape ,gnome ,engine #dhf ,mother ,bod1 ,gnome ,engine #cje ,motor ,misfires1 ,carburetor ,faults ,causing #cgd ,motor ,misfires1 ,ignition ,troubles ,causing #cgj ,motor ,races1 ,carburetor ,faults ,causing #cgd ,motor ,starts ,hard1 ,carburetor ,faults ,causing #cgd ,motor ,stops ,in ,flight1 ,carburetor ,faults #cgd ,motor ,stops ,without ,warning1 ,ignition ,troubles #cgj ,multiple ,cylinder ,engine1 ,why ,best #hc ,multiple ,nozzle ,vaporizers #abi ,multiple ,valve ,advantages #bhf ,n ,noisy ,engine ,operation1 ,causes of #cei ,noisy ,operation1 ,carburetor ,faults ,causing #cgd ,noisy ,operation1 ,summary of ,troubles ,causing #cfe ,o ,offset ,cylinders1 ,reason for #bdc ,oil ,bi-pass1 ,function of #bac ,oil1 ,draining ,from ,crank-case #bad ,oil ,grooves1 ,cutting #ddh ,oil ,pressure in ,hall-,scott ,system #bad ,oil ,pressure ,relief ,bi-pass #bac ,oiling ,system ,defects #ceg ,oils for ,cylinder ,lubrication #bjf ,oils for ,hall-,scott ,engine #bae ,oils for ,lubrication #bjd ,operating ,principles of ,engines #cg ,oscillating ,piston ,pin #bie ,otto ,four-cycle ,cards #fg ,overhauling ,aviation ,engines #dab ,overhead ,cam-shaft ,location #beb ,overheating1 ,causes of #cei ,p ,panhard ,concentric ,valves #bee ,petroleum1 ,distillates of #aaa ,piston1 ,differential #bia ,piston ,pin ,retention #bic ,piston ,ring ,construction #bih ,piston ,ring ,joints #bii ,piston ,ring ,manipulation #dch ,piston ,ring ,troubles #dcg ,piston ,rings1 ,compound #cja ,piston ,rings1 ,concentric #bii ,piston ,rings1 ,eccentric #bii ,piston ,rings1 ,fitting #dci ,piston ,rings1 ,leak ,proof #cja ,piston ,rings1 ,replacing #dda ,piston ,speed in ,airplane ,engines #bda ,piston ,speed1 ,meaning of #bda ,piston ,troubles and ,remedies #dcf ,pistons1 ,aluminum #bif ,pistons1 ,details of #bhh ,pistons for ,two-cycle ,engines #bhi ,positive ,valve ,systems #bhc ,power1 ,affected by ,high ,altitude #ade ,power ,delivery in ,multiple ,cylinder ,engines #ia ,power1 ,how ,obtained ,from ,heat #eh ,power ,needed in ,airplane ,engines #ba ,power ,used in ,airplanes #bf ,precautions in ,assembling ,parts #deb ,pressure ,relief ,fitting #bac ,pressures and ,temperatures #fc ,principles of ,carburetion #aab ,principles of ,magneto ,action #afc ,properties of ,cylinder ,oils #bjg ,properties of ,liquid ,fuels #aaj ,pump ,circulation ,systems #bbf ,pump ,forms #bbf ,r ,radial ,cylinder ,arrangement #ajc ,reading ,indicator ,cards #fg ,reamers1 ,types and ,use #cib ,reassembling ,parts1 ,precautions in #dea ,removable ,cylinder ,head #bci ,renault ,air ,cooled ,engine #ejg ,renault ,engine ,details #ejh ,repairing ,scored ,cylinders #dbc ,requisites for ,best ,power ,effect #ei ,reseating and ,truing ,valves #dbf ,resistance1 ,influence of #bb ,rotary ,cylinder ,engines #ajg ,rotary ,engine1 ,le ,rhone #die ,rotary ,engines1 ,castor ,oil for #baa ,rotary ,engines1 ,installing #cdb ,rotary ,engines1 ,why ,odd ,number of ,cylinders #aji ,rotary ,engines1 ,why ,odd ,number of ,cylinders ,is ,used #dhb ,s ,s4 ,a4 ,e4 ,engine ,bed ,dimensions #ccj ,salmson ,nine-cylinder ,engine #dgj ,schebler ,carburetor #abe ,scissors ,joint ,rods #caj ,scored ,cylinders1 ,repairing #dbb ,scrapers1 ,types of ,bearing #ddf ,scraping ,bearings to ,fit #ddg ,second ,law of ,gases #ej ,sequence of ,engine ,operation #hd ,six-cylinder ,timing ,diagram #bge ,sixteen ,valve ,duesenberg ,engine #ebe ,skipping or ,irregular ,operation1 ,causes of #cfg ,sliding ,sleeve ,valves #bff ,spark ,plug ,air ,gaps1 ,setting #aig ,spark ,plug1 ,design of #aic ,spark ,plug1 ,mica #aid ,spark ,plug1 ,porcelain #aic ,spark ,plugs1 ,defects in #cga ,spark ,plugs for ,two ,spark ,ignition #aig ,spark ,plug1 ,special for ,airplane ,engine #aii ,spark ,plug1 ,standard ,s4 ,a4 ,e4 #aie ,spherical ,combustion ,chambers #gf ,splash ,lubrication #bae ,split ,pin ,remover #chd ,spraying ,carburetors #abj ,springless ,valves #bhj ,springs1 for ,valves #bfc ,spring ,winder #chd ,sprung ,cam-shaft1 ,testing #dea ,stand for ,supporting ,engine #dad ,starting ,engine1 ,hints for #cfa ,starting ,hall-,scott ,engine #cda ,starting ,system1 ,christensen #efg ,starting ,systems1 ,compressed ,air #efe ,starting ,systems1 ,electric #efi ,statistics1 ,american ,engines #edf1 #edg ,statistic ,sheet1 ,hall-,scott ,engines #edd ,statistics of ,benz ,engine #eea ,steam ,engine1 ,efficiency of #ei ,steam ,engine1 ,why ,not ,used #bg ,steel ,scale1 ,machinists' #cii ,stewart ,metering ,pin ,carburetor #abh ,storage ,battery1 ,defects in #cgb ,stroke and ,bore ,ratio #bdj ,sturtevant ,model #e;,a ,engine #eae ,summary of ,engine ,types #cj ,sunbeam ,aviation ,engines #ehh ,sunbeam ,eighteen-,cylinder ,engine #efa ,t ,tap and ,die ,sets #cig ,taps for ,thread ,cutting #cid ,tee ,head ,cylinders #bdg ,temperature ,computations #eb ,temperatures and ,explosive ,pressures #fd ,temperatures and ,pressures #fc ,temperatures1 ,operating #bba ,testing ,bearing ,parallelism #dec ,testing ,connecting ,rod ,alignment #ded ,testing ,fit of ,bearings #ddf ,testing ,sprung ,cam-shaft #dea ,theory of ,gas ,engine #dg ,theory of ,lubrication #bjc ,thermo-syphon ,cooling ,system #bbg ,thomas-,morse ,aviation ,engine #eba ,thomas-,morse ,lubrication ,system #baj ,thread ,pitch ,gauge #djc ,time of ,ignition #bgc ,timer1 ,defects in #cgc ,times of ,explosion #ef ,timing ,dixie ,magneto #ahh ,timing ,gears1 ,effects of ,wear #def ,timing ,magneto #agi ,timing ,valves #bfg ,tool ,outfits1 ,typical #djh ,tools for ,adjusting and ,erecting #cgh ,tools for ,bearing ,work #dde ,tools for ,curtiss ,engines #djh ,tools for ,grinding ,valves #dcj ,tools for ,hall-,scott ,engines #daj1 #daa ,tools for ,measuring #cig ,tools for ,reseating ,valves #dbf ,trouble in ,carburetion ,system #cee ,trouble1 ,location of ,magneto #aha ,troubles1 ,engine1 ,how to ,locate #cde ,troubles1 ,ignition #cec ,troubles in ,oiling ,system #ceg ,true ,high ,tension ,magneto #agb ,twelve-,cylinder ,engines #if ,two-and ,four-,cycle ,types1 ,comparison of #dd ,two-,cycle ,engine ,action #da ,two-,cycle ,three-,port ,engine #dc ,two-,cycle ,two-,port ,engine #db ,two-,spark ,ignition #aif ,two-,stage ,carburetor #aca ,types of ,aircraft #ag ,types of ,internal ,combustion ,engines #cj ,v ,vacuum ,fuel ,feed1 ,stewart #aai ,value of ,compression #fi ,value of ,indicator ,cards #ff ,valve ,actuation1 ,le ,rhone #ejj ,valve ,design and ,construction #bef ,valve-,grinding ,processes #dbi ,valve-,lifting ,cams #bei ,valve-,lifting ,plungers #bfj ,valve ,location ,practice #bde ,valve ,operating ,means #beb ,valve ,operating ,system1 ,depreciation in #dcc ,valve ,operation #beh ,valve ,removal and ,inspection #dbd ,valve ,seating1 ,how to ,test #dcb ,valve ,springs #bfc ,valve ,timing1 ,exhaust #bgj ,valve ,timing1 ,gnome ,monosoupape #bgh ,valve ,timing1 ,intake #bgj ,valve ,timing1 ,lag and ,lead #bfi ,valve ,timing ,procedure #bgg ,valve ,timing ,practice #bfg ,valves1 ,electric ,welded #beh ,valves1 ,flat and ,bevel ,seat #beg ,valves1 ,four per ,cylinder #bhd ,valves1 ,how ,placed in ,cylinder #bdg ,valves in ,cages #bdi ,valves in ,removable ,heads #bdi ,valves1 ,materials ,used for #beh ,valves1 ,reseating #dbf ,vaporizer1 ,simple ,forms of #abj ,v ,engines1 ,cylinder ,arrangement in #ajb ,vernier1 ,how ,used #dja ,w ,wall ,cooling1 ,losses in #fe ,water ,cooling by ,natural ,circulation #bbg ,water ,cooling ,system #bbd ,weight of ,airplane ,motors #ba ,wiring1 ,defects in #cgc ,wiring ,magneto ,ignition ,system #agi ,wisconsin ,engines #eca ,wrenches1 ,forms of #chj ,wrist-pin ,retention #bic ,wrist-pin ,retention ,locks #bie ,wrist-pin ,wear and ,remedy #ddb ,z ,zenith ,carburetor1 ,action of #acg ,zenith ,duplex ,carburetor1 ,troubles in #cef ,zenith ,carburetor ,installation #aci ,,list ,,of ,,illustrations ,frontispiece4 ,part ,sectional ,view of ,hall-,scott ,airplane ,motor1 ,showing ,principal ,parts4 ,fig4 #a4 ,diagrams ,illustrating ,computations for ,horse-,power ,required for ,airplane ,flight4 ,fig4 #b4 ,plate ,showing ,heavy1 ,slow ,speed ,internal ,combustion ,engines ,used ,only for ,stationary ,power in ,large ,installations ,giving ,weight to ,horse-,power ,ratio4 ,fig4 #c4 ,various ,forms of ,internal ,combustion ,engines ,showing ,decrease in ,weight to ,horse-,power ,ratio with ,augmenting ,speed of ,rotation4 ,fig4 #d4 ,internal ,combustion ,engine ,types of ,extremely ,fine ,construction and ,refined ,design1 ,showing ,great ,power ,outputs for ,very ,small ,weight1 a ,feature ,very ,much ,desired in ,airplane ,power ,plants4 ,fig4 #e4 ,outlining ,first ,two ,strokes of ,piston in ,four-,cycle ,engine4 ,fig4 #f4 ,outlining ,second ,two ,strokes of ,piston in ,four-,cycle ,engine4 ,fig4 #g4 ,sectional ,view of ,l ,head ,gasoline ,engine ,cylinder ,showing ,piston ,movements ,during ,four-,stroke ,cycle4 ,fig4 #h4 ,showing ,two-port1 ,two-cycle ,engine ,operation4 ,fig4 #i4 ,defining ,three-port1 ,two-cycle ,engine ,action4 ,fig4 #aj4 ,diagrams ,contrasting ,action of ,two- and ,four-,cycle ,cylinders on ,exhaust and ,intake ,stroke4 ,fig4 #aa4 ,diagram ,isothermal and ,adiabatic ,lines4 ,fig4 #ab4 ,graphic ,diagram ,showing ,approximate ,utilization of ,fuel ,burned in ,internal-,combustion ,engine4 ,fig4 #ac4 ,otto ,four-,cycle ,card4 ,fig4 #ad4 ,diesel ,motor ,card4 ,fig4 #ae4 ,diagram of ,heat in the ,gas ,engine ,cylinder4 ,fig4 #af4 ,chart ,showing ,relation ,between ,compression ,volume and ,pressure4 ,fig4 #ag4 ,the ,thompson ,indicator1 an ,instrument for ,determining ,compressions and ,explosion ,pressure ,values and ,recording ,them on ,chart4 ,fig4 #ah4 ,spherical ,combustion ,chamber4 ,fig4 #ai4 ,enlarged ,combustion ,chamber4 ,fig4 #bj4 ,mercedes ,aviation ,engine ,cylinder ,section ,showing ,approximately ,spherical ,combustion ,chamber and ,concave ,piston ,top4 ,fig4 #ba4 ,side ,sectional ,view of ,typical ,airplane ,engine1 ,showing ,parts and ,their ,relation to ,each ,other4 ,this ,engine is an ,aeromarine ,design and ,utilizes a ,distinctive ,concentric ,valve ,construction4 ,fig4 #bb4 ,diagrams ,illustrating ,sequence of ,cycles in ,one- and ,two-,cylinder ,engines ,showing ,more ,uniform ,turning ,effort on ,crank-,shaft with ,two-,cylinder ,motors4 ,fig4 #bc4 ,diagrams ,demonstrating ,clearly ,advantages which ,obtain when ,multiple-,cylinder ,motors are ,used as ,power ,plants4 ,fig4 #bd4 ,showing ,three ,possible ,though ,unconventional ,arrangements of ,four-,cylinder ,engines4 ,fig4 #be4 ,diagrams ,outlining ,advantages of ,multiple ,cylinder ,motors1 and ,why ,they ,deliver ,power ,more ,evenly ,than ,single ,cylinder ,types4 ,fig4 #bf4 ,diagrams ,showing ,duration of ,events for a ,four-,stroke ,cycle1 ,six-,cylinder ,engine4 ,fig4 #bg4 ,diagram ,showing ,actual ,duration of ,different ,strokes in ,degrees4 ,fig4 #bh4 ,another ,diagram to ,facilitate ,understanding ,sequence of ,functions in ,six-,cylinder ,engine4 ,fig4 #bi4 ,types of ,eight-,cylinder ,engines ,showing the ,advantage of the ,v ,method of ,cylinder ,placing4 ,fig4 #cj4 ,curves ,showing ,torque of ,various ,engine ,types ,demonstrate ,graphically ,marked ,advantage of the ,eight-,cylinder ,type4 ,fig4 #ca4 ,diagrams ,showing ,how ,increasing ,number of ,cylinders ,makes for ,more ,uniform ,power ,application4 ,fig4 #cb4 ,how the ,angle ,between the ,cylinders of an ,eight- and ,twelve-,cylinder ,v ,motor ,varies4 ,fig4 #cc4 ,the ,hall-,scott ,four-,cylinder #ajj ,horse-,power ,aviation ,motor4 ,fig4 #cd4 ,two ,views of the ,duesenberg ,sixteen ,valve ,four-,cylinder ,aviation ,motor4 ,fig4 #ce4 ,the ,hall-,scott ,six-,cylinder ,aviation ,engine4 ,fig4 #cf4 ,the ,curtiss ,eight-,cylinder1 #bjj ,horse-,power ,aviation ,engine4 ,fig4 #cg4 ,the ,sturtevant ,eight-,cylinder1 ,high ,speed ,aviation ,motor4 ,fig4 #ch4 ,anzani #dj-ej ,horse-,power ,five-,cylinder ,air ,cooled ,engine4 ,fig4 #ci4 ,unconventional ,six-,cylinder ,aircraft ,motor of ,masson ,design4 ,fig4 #dj4 ,the ,gnome ,fourteen-,cylinder ,revolving ,motor4 ,fig4 #da4 ,how ,gravity ,feed ,fuel ,tank ,may ,be ,mounted ,back of ,engine and ,secure ,short ,fuel ,line4 ,fig4 #db4 ,the ,stewart ,vacuum ,fuel ,feed ,tank4 ,fig4 #dc4 ,marine-,type ,mixing ,valve1 by which ,gasoline is ,sprayed into ,air ,stream ,through ,small ,opening in ,air-,valve ,seat4 ,fig4 #dd4 ,tracing ,evolution of ,modern ,spray ,carburetor4 ,a--,early ,form ,evolved by ,maybach4 ,b4--,phoenix-,daimler ,modification of ,maybach's ,principle4 ,c--,modern ,concentric ,float ,automatic ,compensating ,carburetor4 ,fig4 #de4 ,new ,model of ,schebler ,carburetor ,with ,metering ,valve and ,extended ,venturi4 ,note ,mechanical ,connection ,between ,air ,valve and ,fuel ,regulating ,needle4 ,fig4 #df4 ,the ,claudel ,carburetor4 ,fig4 #dg4 ,the ,stewart ,metering ,pin ,carburetor4 ,fig4 #dh4 ,the ,ball and ,ball ,two-,stage ,carburetor4 ,fig4 #di4 ,the ,master ,carburetor4 ,fig4 #ej4 ,sectional ,view of ,master ,carburetor ,showing ,parts4 ,fig4 #ea4 ,sectional ,view of ,zenith ,compound ,nozzle ,compensating ,carburetor4 ,fig4 #eb4 ,diagrams ,explaining ,action of ,baverey ,compound ,nozzle ,used in ,zenith ,carburetor4 ,fig4 #ec4 ,the ,zenith ,duplex ,carburetor for ,airplane ,motors of the ,v ,type4 ,fig4 #ed4 ,rear ,view of ,curtiss ,,ox-#b #ij ,horse-,power ,airplane ,motor ,showing ,carburetor ,location and ,hot ,air ,leads4 ,fig4 #ee4 ,types of ,strainers ,interposed ,between ,vaporizer and ,gasoline ,tank to ,prevent ,water or ,dirt ,passing ,into ,carbureting ,device4 ,fig4 #ef4 ,chart ,showing ,diminution of ,air ,pressure as ,altitude ,increases4 ,fig4 #eg4 ,some ,simple ,experiments to ,demonstrate ,various ,magnetic ,phenomena and ,clearly ,outline ,effects of ,magnetism and ,various ,forms of ,magnets4 ,fig4 #eh4 ,elementary ,form of ,magneto ,showing ,principal ,parts ,simplified to ,make ,method of ,current ,generation ,clear4 ,fig4 #ei4 ,showing ,how ,strength of ,magnetic ,influence and of the ,currents ,induced in the ,windings of ,armature ,vary with the ,rapidity of ,changes of ,flow4 ,fig4 #fj4 ,diagrams ,explaining ,action of ,low ,tension ,transformer ,coil and ,true ,high ,tension ,magneto ,ignition ,systems4 ,fig4 #fj;,a4 ,side ,sectional ,view of ,bosch ,high-,tension ,magneto ,shows ,disposition of ,parts4 ,end ,elevation ,depicts ,arrangement of ,interruptor and ,distributor ,mechanism4 ,fig4 #fa4 ,berling ,two-,spark ,dual ,ignition ,system4 ,fig4 #fb4 ,berling ,double-,spark ,independent ,system4 ,fig4 #fc4 ,type ,,dd ,berling ,high ,tension ,magneto4 ,fig4 #fd4 ,wiring ,diagrams of ,berling ,magneto ,ignition ,systems4 ,fig4 #fe4 ,the ,berling ,magneto ,breaker ,box ,showing ,contact ,points ,separated and ,interruptor ,lever on ,cam4 ,fig4 #ff4 ,the ,dixie ,model #fj for ,six-,cylinder ,airplane ,engine ,ignition4 ,fig4 #fg4 ,installation ,dimensions of ,dixie ,model #fj ,magneto4 ,fig4 #fh4 ,the ,rotating ,elements of the ,dixie ,magneto4 ,fig4 #fi4 ,suggestions for ,adjusting and ,dismantling ,dixie ,magneto4 ,a--,screw ,driver ,adjusts ,contact ,points4 ,b--,distributor ,block ,removed4 ,c--,taking off ,magnets4 ,d--,showing ,how ,easily ,condenser and ,high ,tension ,windings are ,removed4 ,fig4 #fi;,a4 ,sectional ,views ,outlining ,construction of ,dixie ,magneto with ,compound ,distributor for ,eight-,cylinder ,engine ,ignition4 ,fig4 #gj4 ,wiring ,diagram of ,dixie ,magneto ,installation on ,hall-,scott ,six-,cylinder #abe ,horse-,power ,aeronautic ,motor4 ,fig4 #ga4 ,how ,magneto ,ignition is ,installed on ,thomas-,morse #ace ,horse-,power ,motor4 ,fig4 #gb4 ,spark-,plug ,types ,showing ,construction and ,arrangement of ,parts4 ,fig4 #gc4 ,standard ,airplane ,engine ,plug ,suggested by ,s4 ,a4 ,e4 ,standards ,committee4 ,fig4 #gd4 ,special ,mica ,plug for ,aviation ,engines4 ,fig4 #ge4 ,showing ,use of ,magnifying ,glass to ,demonstrate that ,apparently ,smooth ,metal ,surfaces ,may ,have ,minute ,irregularities which ,produce ,friction4 ,fig4 #gf4 ,pressure ,feed ,oiling ,system of ,thomas ,aviation ,engine ,includes ,oil ,cooling ,means4 ,fig4 #gg4 ,diagram of ,oiling ,system1 ,hall-,scott ,type ,a #abe ,horse-,power ,engine4 ,fig4 #gh4 ,sectional ,view of ,typical ,motor ,showing ,parts ,needing ,lubrication and ,method of ,applying ,oil by ,constant ,level ,splash ,system4 ,note also ,water ,jacket and ,spaces for ,water ,circulation4 ,fig4 #gi4 ,pressure ,feed ,oil-,supply ,system of ,airplane ,power ,plants has ,many ,good ,features4 ,fig4 #hj4 ,why ,pressure ,feed ,system is ,best for ,eight-,cylinder ,vee ,airplane ,engines4 ,fig4 #ha4 ,operating ,temperatures of ,automobile ,engine ,parts ,useful as a ,guide to ,understand ,airplane ,power ,plant ,heat4 ,fig4 #hb4 ,water ,cooling of ,salmson ,seven-,cylinder ,radial ,airplane ,engine4 ,fig4 #hc4 ,how ,water ,cooling ,system of ,thomas ,airplane ,engine is ,installed in ,fuselage4 ,fig4 #hd4 ,finned ,tube ,radiators at the ,side of ,hall-,scott ,airplane ,power ,plant ,installed in ,standard ,fuselage4 ,fig4 #he4 ,anzani ,testing ,his ,five-,cylinder ,air ,cooled ,aviation ,motor ,installed in ,bleriot ,monoplane4 ,note ,exposure of ,flanged ,cylinders to ,propeller ,slip ,stream4 ,fig4 #hf4 ,views of ,four-,cylinder ,duesenberg ,airplane ,engine ,cylinder ,block4 ,fig4 #hg4 ,twin-,cylinder ,block of ,sturtevant ,airplane ,engine is ,cast of ,aluminum1 and ,has ,removable ,cylinder ,head4 ,fig4 #hh4 ,aluminum ,cylinder ,pair ,casting of ,thomas #aej ,horse-,power ,airplane ,engine is of the ,l ,head ,type4 ,fig4 #ij4 ,cross ,section of ,austro-,daimler ,engine1 ,showing ,offset ,cylinder ,construction4 ,note ,applied ,water ,jacket and ,peculiar ,valve ,action4 ,fig4 #ia4 ,diagrams ,demonstrating ,advantages of ,offset ,crank-,shaft ,construction4 ,fig4 #ib4 ,diagram ,showing ,forms of ,cylinder ,demanded by ,different ,valve ,placings4 ,a--,t ,head ,type1 ,valves on ,opposite ,sides4 ,b--,l ,head ,cylinder1 ,valves ,side by ,side4 ,c--,l ,head ,cylinder1 ,one ,valve in ,head1 ,other in ,pocket4 ,d--,inlet ,valve ,over ,exhaust ,member1 ,both in ,side ,pocket4 ,e--,valve-in-the-,head ,type with ,vertical ,valves4 ,f--,inclined ,valves ,placed to ,open ,directly into ,combustion ,chamber4 ,fig4 #ic4 ,sectional ,view of ,engine ,cylinder ,showing ,valve and ,cage ,installation4 ,fig4 #id4 ,diagrams ,showing ,how ,gas ,enters ,cylinder ,through ,overhead ,valves and ,other ,types4 ,a--,tee ,head ,cylinder4 ,b--,l ,head ,cylinder4 ,c--,overhead ,valve4 ,fig4 #ie4 ,conventional ,methods of ,operating ,internal ,combustion ,motor ,valves4 ,fig4 #if4 ,examples of ,direct ,valve ,actuation by ,overhead ,cam-,shaft4 ,a--,mercedes4 ,b--,hall-,scott4 ,c--,wisconsin4 ,fig4 #ig4 ,,censored ,fig4 #ih4 ,,censored ,fig4 #ii4 ,sectional ,views ,showing ,arrangement of ,novel ,concentric ,valve ,arrangement ,devised by ,panhard for ,aerial ,engines4 ,fig4 #ajj4 ,showing ,clearance ,allowed ,between ,valve ,stem and ,valve ,stem ,guide to ,secure ,free ,action4 ,fig4 #aja4 ,forms of ,valve-,lifting ,cams ,generally ,employed4 ,a--,cam ,profile for ,long ,dwell and ,quick ,lift4 ,b--,typical ,inlet ,cam ,used with ,mushroom ,type ,follower4 ,c--,average ,form of ,cam4 ,d--,designed to ,give ,quick ,lift and ,gradual ,closing4 ,fig4 #ajb4 ,showing ,principal ,types of ,cam ,followers which ,have ,received ,general ,application4 ,fig4 #ajc4 ,diagram ,showing ,proper ,clearance to ,allow ,between ,adjusting ,screw and ,valve ,stems in ,hall-,scott ,aviation ,engines4 ,fig4 #ajd4 ,cam-,shaft of ,thomas ,airplane ,motor ,has ,cams ,forged ,integral4 ,note ,split ,cam-,shaft ,bearings and ,method of ,gear ,retention4 ,fig4 #aje4 ,section ,through ,cylinder of ,knight ,motor1 ,showing ,important ,parts of ,valve ,motion4 ,fig4 #ajf4 ,diagrams ,showing ,knight ,sleeve ,valve ,action4 ,fig4 #ajg4 ,cross ,sectional ,view of ,knight ,type ,eight ,cylinder ,v ,engine4 ,fig4 #ajh4 ,diagrams ,explaining ,valve and ,ignition ,timing of ,hall-,scott ,aviation ,engine4 ,fig4 #aji4 ,timing ,diagram of ,typical ,six-,cylinder ,engine4 ,fig4 #aaj4 ,timing ,diagram of ,typical ,eight-,cylinder ,v ,engine4 ,fig4 #aaa4 ,timing ,diagram ,showing ,peculiar ,valve ,timing of ,gnome ,monosoupape ,rotary ,motor4 ,fig4 #aab4 ,two ,methods of ,operating ,valves by ,positive ,cam ,mechanism ,which ,closes as ,well as ,opens ,them4 ,fig4 #aac4 ,diagram ,comparing ,two ,large ,valves and ,four ,small ,ones of ,practically the ,same ,area4 ,note ,how ,easily ,small ,valves are ,installed to ,open ,directly ,into the ,cylinder4 ,fig4 #aad4 ,sectional ,views of ,sixteen-,valve ,four-,cylinder ,automobile ,racing ,engine ,that ,may ,have ,possibilities for ,aviation ,service4 ,fig4 #aae4 ,front ,view of ,curtiss ,,ox-#c ,aviation ,motor1 ,showing ,unconventional ,valve ,action by ,concentric ,push ,rod and ,pull ,tube4 ,fig4 #aaf4 ,forms of ,pistons ,commonly ,employed in ,gasoline ,engines4 ,a--,dome ,head ,piston and ,three ,packing ,rings4 ,b--,flat ,top ,form ,almost ,universally ,used4 ,c--,concave ,piston ,utilized in ,knight ,motors and ,some ,having ,overhead ,valves4 ,d--,two-,cycle ,engine ,member with ,deflector ,plate ,cast ,integrally4 ,e--,differential of ,two-,diameter ,piston ,used in ,some ,engines ,operating on ,two-,cycle ,principle4 ,fig4 #aag4 ,typical ,methods of ,piston ,pin ,retention ,generally ,used in ,engines of ,american ,design4 ,a--,single ,set ,screw and ,lock ,nut4 ,b--,set ,screw and ,check ,nut ,fitting ,groove in ,wrist ,pin4 ,c1 ,d--,two ,locking ,screws ,passing ,into ,interior of ,hollow ,wrist ,pin4 ,e--,split ,ring ,holds ,pin in ,place4 ,f--,use of ,taper ,expanding ,plugs ,outlined4 ,g--,spring ,pressed ,plunger ,type4 ,h--,piston ,pin ,pinned to ,connecting ,rod4 ,i--,wrist ,pin ,clamped in ,connecting ,rod ,small ,end by ,bolt4 ,fig4 #aah4 ,typical ,piston and ,connecting ,rod ,assembly4 ,fig4 #aai4 ,parts of ,sturtevant ,aviation ,engine4 ,a--,cylinder ,head ,showing ,valves4 ,b--,connecting ,rod4 ,c--,piston and ,rings4 ,fig4 #abj4 ,aluminum ,piston and ,light ,but ,strong ,steel ,connecting ,rod and ,wrist ,pin of ,thomas ,aviation ,engine4 ,fig4 #aba4 ,cast ,iron ,piston of ,monosoupape ,gnome ,engine ,installed ,on ,one of the ,short ,connecting ,rods4 ,fig4 #abb4 ,types of ,aluminum ,pistons ,used ,in ,aviation ,engines4 ,fig4 #abc4 ,types of ,piston ,rings and ,ring ,joints4 ,a--,concentric ,ring4 ,b--,eccentrically ,machined ,form4 ,c--,lap ,joint ,ring4 ,d--,butt ,joint1 ,seldom ,used4 ,e--,diagonal ,cut ,member1 a ,popular ,form4 ,fig4 #abd4 ,diagrams ,showing ,advantages of ,concentric ,piston ,rings4 ,fig4 #abe4 ,leak-,proof and ,other ,compound ,piston ,rings4 ,fig4 #abf4 ,sectional ,view of ,engine ,showing ,means of ,preventing ,oil ,leakage ,by ,piston ,rings4 ,fig4 #abg4 ,connecting ,rod and ,crank-,shaft ,construction of ,gnome ,monosoupape ,engine4 ,fig4 #abh4 ,connecting ,rod ,types ,summarized4 ,a--,single ,connecting ,rod ,made in ,one ,piece1 ,usually ,fitted in ,small ,single-,cylinder ,engines ,having ,built-,up ,crank-,shafts4 ,b--,marine ,type1 a ,popular ,form on ,heavy ,engines4 ,c--,conventional ,automobile ,type1 a ,modified ,marine ,form4 ,d--,type ,having ,hinged ,lower ,cap and ,split ,wrist ,pin ,bushing4 ,e--,connecting ,rod ,having ,diagonally ,divided ,big ,end4 ,f--,ball-,bearing ,rod4 ,g--,sections ,showing ,structural ,shapes ,commonly ,employed in ,connecting ,rod ,construction4 ,fig4 #abi4 ,double ,connecting ,rod ,assembly ,for ,use ,on ,single ,crank-,pin of ,vee ,engine4 ,fig4 #acj4 ,another ,type of ,double ,connecting ,rod for ,vee ,engines4 ,fig4 #aca4 ,part ,sectional ,view of ,wisconsin ,aviation ,engine1 ,showing ,four-,bearing ,crank-,shaft1 ,overhead ,cam-,shaft1 and ,method of ,combining ,cylinders in ,pairs4 ,fig4 #acb4 ,part ,sectional ,view of ,renault ,twelve-,cylinder ,water-,cooled ,engine1 ,showing ,connecting ,rod ,construction and ,other ,important ,internal ,parts4 ,fig4 #acc4 ,typical ,cam-,shaft1 with ,valve ,lifting ,cams and ,gears to ,operate ,auxiliary ,devices ,forged ,integrally4 ,fig4 #acd4 ,important ,parts of ,duesenberg ,aviation ,engine4 ,a--,three ,main ,bearing ,crank-,shaft4 ,b--,cam-,shaft with ,integral ,cams4 ,c--,piston and ,connecting ,rod ,assembly4 ,d--,valve ,rocker ,group4 ,e--,piston4 ,f--,main ,bearing ,brasses4 ,fig4 #ace4 ,showing ,method of ,making ,crank-,shaft4 ,a--,the ,rough ,steel ,forging ,before ,machining4 ,b--,the ,finished ,six-,throw1 ,seven-,bearing ,crank-,shaft4 ,fig4 #acf4 ,showing ,form of ,crank-,shaft for ,twin-,cylinder ,opposed ,power ,plant4 ,fig4 #acg4 ,crank-,shaft of ,thomas-,morse ,eight-,cylinder ,vee ,engine4 ,fig4 #ach4 ,crank-,case and ,crank-,shaft ,construction for ,twelve-,cylinder ,motors4 ,a--,duesenberg4 ,b--,curtiss4 ,fig4 #aci4 ,counterbalanced ,crank-,shafts ,reduce ,engine ,vibration and ,permit of ,higher ,rotative ,speeds4 ,fig4 #adj4 ,view of ,thomas #ace ,horse-,power ,aeromotor1 ,model #h1 ,showing ,conventional ,method of ,crank-,case ,construction4 ,fig4 #ada4 ,views of ,upper ,half of ,thomas ,aeromotor ,crank-,case4 ,fig4 #adb4 ,method of ,constructing ,eight-,cylinder ,vee ,engine1 ,possible if ,aluminum ,cylinder and ,crank-,case ,castings are ,used4 ,fig4 #adc4 ,simple and ,compact ,crank-,case1 ,possible ,when ,radial ,cylinder ,engine ,design is ,followed4 ,fig4 #add4 ,unconventional ,mounting of ,german ,inverted ,cylinder ,motor4 ,fig4 #ade4 ,how ,curtiss ,model ,,ox-#b ,motor is ,installed in ,fuselage of ,curtiss ,tractor ,biplane4 ,note ,similarity of ,mounting to ,automobile ,power ,plant4 ,fig4 #adf4 ,latest ,model of ,curtiss ,,jn-#d ,training ,machine1 ,showing ,thorough ,enclosure of ,power ,plant and ,method of ,disposing of the ,exhaust ,gases4 ,fig4 #adg4 ,front ,view of ,l4 ,w4 ,f4 ,tractor ,biplane ,fuselage1 ,showing ,method of ,installing ,thomas ,aeromotor and ,method of ,disposing of ,exhaust ,gases4 ,fig4 #adh4 ,end ,elevation of ,hall-,scott ,a-#g ,four-,cylinder ,motor1 with ,installation ,dimensions4 ,fig4 #adi4 ,plan and ,side ,elevation of ,hall-,scott ,a-#g ,four-,cylinder ,airplane ,engine1 with ,installation ,dimensions4 ,fig4 #aej4 ,,censored ,fig4 #aea4 ,,censored ,fig4 #aeb4 ,,censored ,fig4 #aec4 ,plan ,view of ,hall-,scott ,type ,a-#e #abe ,horse-,power ,airplane ,engine1 ,showing ,installation ,dimensions4 ,fig4 #aed4 ,three-,quarter ,view of ,hall-,scott ,type ,a-#e #abe ,horse-,power ,six-,cylinder ,engine1 with ,one of the ,side ,radiators ,removed to ,show ,installation in ,standard ,fuselage4 ,fig4 #aee4 ,diagram ,showing ,proper ,installation of ,hall-,scott ,type ,a-#e #abe ,horse-,power ,engine with ,pressure ,feed ,fuel ,supply ,system4 ,fig4 #aef4 ,diagram ,defining ,installation of ,gnome ,monosoupape ,motor in ,tractor ,biplane4 ,note ,necessary ,piping for ,fuel1 ,oil1 and ,air ,lines4 ,fig4 #aeg4 ,showing ,two ,methods of ,placing ,propeller on ,gnome ,rotary ,motor4 ,fig4 #aeh4 ,how ,gnome ,rotary ,motor ,may ,be ,attached to ,airplane ,fuselage ,members4 ,fig4 #aei4 ,how ,anzani ,ten-,cylinder ,radial ,engine is ,installed to ,plate ,securely ,attached to ,front ,end of ,tractor ,airplane ,fuselage4 ,fig4 #afj4 ,side ,elevation of ,thomas #ace ,horse-,power ,airplane ,engine1 ,giving ,important ,dimensions4 ,fig4 #afa4 ,front ,elevation of ,thomas-,morse #ace ,horse-,power ,aeromotor1 ,showing ,main ,dimensions4 ,fig4 #afb4 ,front and ,side ,elevations of ,sturtevant ,airplane ,engine1 ,giving ,principal ,dimensions to ,facilitate ,installation4 ,fig4 #afc4 ,practical ,hand ,tools ,useful in ,dismantling and ,repairing ,airplane ,engines4 ,fig4 #afd4 ,wrenches are ,offered in ,many ,forms4 ,fig4 #afe4 ,illustrating ,use and ,care of ,files4 ,fig4 #aff4 ,outlining ,use of ,cotter ,pin ,pliers1 ,spring ,winder1 and ,showing ,practical ,outfit of ,chisels4 ,fig4 #afg4 ,forms of ,hand ,operated ,drilling ,machines4 ,fig4 #afh4 ,forms of ,drills ,used in ,hand and ,power ,drilling ,machines4 ,fig4 #afi4 ,useful ,set of ,number ,drills1 ,showing ,stand for ,keeping ,these in an ,orderly ,manner4 ,fig4 #agj4 ,illustrating ,standard ,forms of ,hand and ,machine ,reamers4 ,fig4 #aga4 ,tools for ,thread ,cutting4 ,fig4 #agb4 ,showing ,holder ,designs for ,one- and ,two-,piece ,thread ,cutting ,dies4 ,fig4 #agc4 ,useful ,outfit of ,taps and ,dies for the ,engine ,repair ,shop4 ,fig4 #agd4 ,common ,forms of ,inside and ,outside ,calipers4 ,fig4 #age4 ,measuring ,appliances for the ,machinist and ,floor ,man4 ,fig4 #agf4 ,at ,left1 ,special ,form of ,vernier ,caliper for ,measuring ,gear ,teeth2 at ,right1 ,micrometer for ,accurate ,internal ,measurements4 ,fig4 #agg4 ,measuring ,appliances of ,value in ,airplane ,repair ,work4 ,fig4 #agh4 ,standard ,forms of ,micrometer ,caliper for ,external ,measurements4 ,fig4 #agi4 ,special ,tools for ,maintaining ,curtiss ,,ox-#b ,motor ,used in ,curtiss ,,jn-#d ,training ,biplane4 ,fig4 #ahj4 ,special ,tools and ,appliances to ,facilitate ,overhauling ,work on ,hall-,scott ,airplane ,engines4 ,fig4 #aha4 ,special ,stand to ,make ,motor ,overhauling ,work ,easier4 ,fig4 #ahb4 ,showing ,where ,carbon ,deposits ,collect in ,engine ,combustion ,chamber1 and ,how to ,burn ,them ,out with the ,aid of ,oxygen4 ,a--,special ,torch4 ,b--,torch ,coupled to ,oxygen ,tank4 ,c--,torch in ,use4 ,fig4 #ahba_/b4 ,part ,sectional ,view1 ,showing ,valve ,arrangement in ,cylinder of ,curtiss ,,ox-#b ,aviation ,engine4 ,fig4 #ahc4 ,tools for ,restoring ,valve ,head and ,seats4 ,fig4 #ahd4 ,tools and ,processes ,utilized in ,valve ,grinding4 ,fig4 #ahe4 ,outlining ,points in ,valve ,operating ,mechanism ,where ,depreciation is ,apt to ,exist4 ,fig4 #ahf4 ,method of ,removing ,piston ,rings1 and ,simple ,clamp to ,facilitate ,insertion of ,rings in ,cylinder4 ,fig4 #ahg4 ,tools and ,processes ,used in ,refitting ,engine ,bearings4 ,fig4 #ahh4 ,showing ,points to ,observe ,when ,fitting ,connecting ,rod ,brasses4 ,fig4 #ahi4 ,methods of ,testing to ,insure ,parallelism of ,bearings ,after ,fitting4 ,fig4 #aij4 ,views ,outlining ,construction of ,three-,cylinder ,anzani ,aviation ,motor4 ,fig4 #aij;a4 ,illustrations ,depicting ,wrong and ,right ,methods of ,swinging the ,stick to ,start ,airplane ,engine4 ,at ,top1 ,poor ,position to ,get ,full ,throw and ,get ,out of the ,way4 ,below1 ,correct ,position to ,get ,quick ,turn ,over of ,crank-,shaft and ,spring ,away from ,propeller4 ,fig4 #aia4 ,the ,anzani ,six-,cylinder ,water-,cooled ,aviation ,engine4 ,fig4 #aib4 ,sectional ,view of ,anzani ,six-,cylinder ,water-,cooled ,aviation ,engine4 ,fig4 #aic4 ,three-,cylinder ,anzani ,air-,cooled ,y-,form ,engine4 ,fig4 #aid4 ,anzani ,fixed ,crank-,case ,engine of the ,six-,cylinder ,form ,utilizes ,air ,cooling ,successfully4 ,fig4 #aie4 ,sectional ,view ,showing ,internal ,parts of ,six-,cylinder ,anzani ,engine1 with ,starwise ,disposition of ,cylinders4 ,fig4 #aif4 ,the ,anzani ,ten-,cylinder ,aviation ,engine at the ,left1 and the ,twenty-,cylinder ,fixed ,type at the ,right4 ,fig4 #aig4 ,application of ,r4 ,e4 ,p4 ,five-,cylinder ,fan-,shape ,air-,cooled ,motor to ,early ,monoplane4 ,fig4 #aih4 ,the ,canton and ,unne ,nine-,cylinder ,water-,cooled ,radial ,engine4 ,fig4 #aii4 ,sectional ,view ,showing ,construction of ,canton and ,unne ,water-,cooled ,radial ,cylinder ,engine4 ,fig4 #bjj4 ,sectional ,view ,outlining ,construction of ,early ,type ,gnome ,valve-in-,piston ,type ,motor4 ,fig4 #bja4 ,sectional ,view of ,early ,type ,gnome ,cylinder and ,piston ,showing ,construction and ,application of ,inlet and ,exhaust ,valves4 ,fig4 #bjb4 ,details of ,old ,style ,gnome ,motor ,inlet and ,exhaust ,valve ,construction and ,operation4 ,fig4 #bjc4 ,the ,gnome ,fourteen-,cylinder #ajj ,horse-,power ,aviation ,engine4 ,fig4 #bjd4 ,cam and ,cam-,gear ,case of the ,gnome ,seven-,cylinder ,revolving ,engine4 ,fig4 #bje4 ,diagrams ,showing ,why ,an ,odd ,number of ,cylinders is ,best for ,rotary ,cylinder ,motors4 ,fig4 #bjf4 ,simple ,carburetor ,used ,on ,early ,gnome ,engines ,attached to ,fixed ,crank-,shaft ,end4 ,fig4 #bjg4 ,sectional ,views of the ,gnome ,oil ,pump4 ,fig4 #bjh4 ,simplified ,diagram ,showing ,gnome ,motor ,magneto ,ignition ,system4 ,fig4 #bji4 ,the ,g4 ,v4 ,gnome ,monosoupape ,nine-,cylinder ,rotary ,engine ,mounted on ,testing ,stand4 ,fig4 #baj4 ,sectional ,view ,showing ,construction of ,general ,vehicle ,co4 ,monosoupape ,gnome ,engine4 ,fig4 #baa4 ,how a ,gnome ,cylinder is ,reduced from ,solid ,chunk of ,steel ,weighing #ig ,pounds to ,finished ,cylinder ,weighing #ea_/b ,pounds4 ,fig4 #bab4 ,the ,gnome ,engine ,cam-,gear ,case1 a ,fine ,example of ,accurate ,machine ,work4 ,fig4 #bac4 ,g4 ,v4 ,gnome ,monosoupape1 with ,cam-,case ,cover ,removed to ,show ,cams and ,valve-,operating ,plungers with ,roller ,cam ,followers4 ,fig4 #bad4 ,the #ej ,horse-,power ,rotary ,bayerischen ,motoren ,gesellschaft ,engine1 a ,german ,adaptation of the ,early ,gnome ,design4 ,fig4 #bae4 ,nine-,cylinder ,revolving ,le ,rhone ,type ,aviation ,engine4 ,fig4 #baf4 ,part ,sectional ,views of ,le ,rhone ,rotary ,cylinder ,engine1 ,showing ,method of ,cylinder ,retention1 ,valve ,operation and ,novel ,crank ,disc ,assembly4 ,fig4 #bag4 ,side ,sectional ,view of ,le ,rhone ,aviation ,engine4 ,fig4 #bah4 ,view ,showing ,le ,rhone ,valve ,action and ,connecting ,rod ,big ,end ,arrangement4 ,fig4 #bai4 ,diagrams ,showing ,important ,components of ,le ,rhone ,motor4 ,fig4 #bbj4 ,how the ,cams of the ,le ,rhone ,motor ,can ,operate ,two ,valves with a ,single ,push ,rod4 ,fig4 #bba4 ,the ,le ,rhone ,carburetor at ,a and ,fuel ,supply ,regulating ,device at ,b4 ,fig4 #bbb4 ,diagrams ,showing ,le ,rhone ,motor ,action and ,firing ,order4 ,fig4 #bbc4 ,diagram ,showing ,positions of ,piston in ,le ,rhone ,rotary ,cylinder ,motor4 ,fig4 #bbd4 ,diagrams ,showing ,valve ,timing of ,le ,rhone ,aviation ,engine4 ,fig4 #bbe4 ,diagrams ,showing ,how ,cylinder ,cooling is ,effected in ,renault ,vee ,engines4 ,fig4 #bbf4 ,end ,sectional ,view of ,renault ,air-,cooled ,aviation ,engine4 ,fig4 #bbg4 ,side ,sectional ,view of ,renault ,twelve-,cylinder ,air-,cooled ,aviation ,engine ,crank-,case1 ,showing ,use of ,plain and ,ball ,bearings for ,crank-,shaft ,support4 ,fig4 #bbh4 ,end ,view of ,renault ,twelve-,cylinder ,engine ,crank-,case1 ,showing ,magneto ,mounting4 ,fig4 #bbi4 ,diagram ,outlining ,renault ,twelve-,cylinder ,engine ,ignition ,system4 ,fig4 #bcj4 ,the ,simplex ,model ,a ,hispano-,suiza ,aviation ,engine1 a ,very ,successful ,form4 ,fig4 #bca4 ,the ,curtiss ,,oxx-#e ,aviation ,engine is an ,eight-,cylinder ,type ,largely ,used on ,training ,machines4 ,fig4 #bcb4 ,top and ,bottom ,views of the ,curtiss ,,oxx-#e #ajj ,horse-,power ,aviation ,engine4 ,fig4 #bcc4 ,end ,view of ,thomas-,morse #aej ,horse-,power ,aluminum ,cylinder ,aviation ,motor ,having ,detachable ,cylinder ,heads4 ,fig4 #bcd4 ,side ,view of ,thomas-,morse ,high ,speed #aej ,horse-,power ,aviation ,motor with ,geared ,down ,propeller ,drive4 ,fig4 #bce4 ,the ,reduction ,gear-,case of ,thomas-,morse #aej ,horse-,power ,aviation ,motor1 ,showing ,ball ,bearing and ,propeller ,drive ,shaft ,gear4 ,fig4 #bcf4 ,the ,six-,cylinder ,aeromarine ,engine4 ,fig4 #bcg4 ,the ,wisconsin ,aviation ,engine1 at ,top1 as ,viewed from ,carburetor ,side4 ,below1 the ,exhaust ,side4 ,fig4 #bch4 ,dimensioned ,end ,elevation of ,wisconsin ,six ,motor4 ,fig4 #bci4 ,dimensioned ,side ,elevation of ,wisconsin ,six ,motor4 ,fig4 #bdj4 ,power1 ,torque and ,efficiency ,curves of ,wisconsin ,aviation ,motor4 ,fig4 #bda4 ,timing ,diagram1 ,wisconsin ,aviation ,engine4 ,fig4 #bdb4 ,dimensioned ,end ,view of ,wisconsin ,twelve-,cylinder ,airplane ,motor4 ,fig4 #bdc4 ,dimensioned ,side ,elevation of ,wisconsin ,twelve-,cylinder ,airplane ,motor4 ,fig4 #bdd4 ,side and ,end ,sectional ,views of ,four-,cylinder ,argus ,engine1 a ,german #ajj ,horse-,power ,design ,having ,bore and ,stroke of #adj mm41 or #e4fj inches1 and ,developing ,its ,power at #a1cfh ,r4,p4,m4 ,weight1 #cej ,pounds4 ,fig4 #bde4 ,part ,sectional ,view of #ij ,horse-,power ,mercedes ,engine1 ,which is ,typical of the ,design of ,larger ,sizes4 ,fig4 #bdf4 ,part ,sectional ,side ,view and ,sectional ,end ,view of ,benz #afj ,horse-,power ,aviation ,engine4 ,fig4 #bdg4 ,at ,top1 the ,sunbeam ,overhead ,valve #agj ,horse-,power ,six-,cylinder ,engine4 ,below1 ,side ,view of ,sunbeam #cej ,horse-,power ,twelve-,cylinder ,vee ,engine4 ,fig4 #bdh4 ,side ,view of ,eighteen-,cylinder ,sunbeam ,coatalen ,aircraft ,engine ,rated at #dge ,b4,h4,p4 ,fig4 #bdi4 ,sunbeam ,eighteen-,cylinder ,motor1 ,viewed from ,pump and ,magneto ,end4 ,fig4 #bej4 ,propeller ,end of ,sunbeam ,eighteen-,cylinder #dge ,b4,h4,p4 ,aviation ,engine4 ,fig4 #bea4 ,view of ,airplane ,cowl ,board1 ,showing the ,various ,navigating and ,indicating ,instruments to ,aid the ,aviator in ,flight4 ,fig4 #beb4 ,parts of ,christensen ,air ,starting ,system ,shown at ,a1 and ,application of ,piping and ,check ,valves to ,cylinders of ,thomas-,morse ,aeromotor ,outlined at ,b4 ,fig4 #bec4 ,diagrams ,showing ,installation of ,air ,starting ,system on ,thomas-,morse ,aviation ,motor4 ,,catalogue ,of the ,,latest and ,,best ,,practical and ,,mechanical ,,books ,including ,automobile and ,aviation ,books ,illustration ,any of these books will be sent prepaid to any part of the world1 on receipt of price4 ,remit by ,draft1 ,postal ,order1 ,express ,order or ,registered ,letter ,published and ,for ,sale ,by ,the ,norman ,w4 ,henley ,publishing ,co41 #b ,west #deth ,street1 ,new ,york1 ,u4,s4,a4 ,,index ,,pages ,air ,brakes #ba1 #bd ,arithmetic #ad1 #be1 #ca ,automobile ,books #c1 #d1 #e1 #f ,automobile ,charts #f1 #g ,automobile ,ignition ,systems #e ,automobile ,lighting #e ,automobile ,questions and ,answers #d ,automobile ,repairing #d ,automobile ,starting ,systems #e ,automobile ,trouble ,charts #e1 #f ,automobile ,welding #e ,aviation #g ,aviation ,chart #g ,batteries1 ,storage #e ,bevel ,gear #ai ,boiler-,room ,chart #i ,brazing #g ,cams #ai ,carburetion ,trouble ,chart #f ,change ,gear #ai ,charts #f1 #g1 #h ,coal #bb ,coke #i ,combustion #bb ,compressed ,air #aj ,concrete #aj1 #aa1 #ab ,concrete for ,farm ,use #aa ,concrete for ,shop ,use #aa ,cosmetics #bg ,cyclecars #e ,dictionary #ab ,dies #ab1 #ac ,drawing #ac1 #ad ,drawing for ,plumbers #bh ,drop ,forging #ac ,dynamo ,building #ad ,electric ,bells #ad ,electric ,switchboards #ad1 #af ,electric ,toy ,making #ae ,electric ,wiring #ad1 #ae1 #af ,electricity #ad1 #ae1 #af1 #ag ,encyclopedia #bd ,e-,t ,air ,brake #bd ,every-day ,engineering #cd ,factory ,management #ag ,ford ,automobile #c ,ford ,trouble ,chart #f ,formulas and ,recipes #bi ,fuel #ag ,gas ,construction #ah ,gas ,engines #ah1 #ai ,gas ,tractor #cc ,gearing and ,cams #ai ,glossary of ,aviation ,terms #g1 #ab ,heating #ca1 #cb ,horse-,power ,chart #i ,hot-,water ,heating #ca1 #cb ,house ,wiring #ae1 #ag ,how to ,run an ,automobile #c ,hydraulics #e ,ice and ,refrigeration #bj ,ignition ,systems #e ,ignition-,trouble ,chart #f ,india ,rubber #cj ,interchangeable ,manufacturing #bd ,inventions #bj ,knots #bj ,lathe ,work #bj ,link ,motions #bb ,liquid ,air #ba ,locomotive ,boilers #bb ,locomotive ,breakdowns #bb ,locomotive ,engineering #ba1 #bb1 #bc1 #bd ,machinist ,book #bd1 #be1 #bf ,magazine1 ,mechanical #cd ,manual ,training #bf ,marine ,engineering #bf ,marine ,gasoline ,engines #ai ,mechanical ,drawing #ac1 #ad ,mechanical ,magazine #cd ,mechanical ,movements #be ,metal ,work #ab1 #ac ,motorcycles #e1 #f ,patents #bj ,pattern ,making #bg ,perfumery #bg ,perspective #ac ,plumbing #bh1 #bi ,producer ,gas #ai ,punches #ac ,questions and ,answers on ,automobile #d ,questions on ,heating #cb ,railroad ,accidents #bc ,railroad ,charts #i ,recipe ,book #bi ,refrigeration #bj ,repairing ,automobiles #d ,rope ,work #bj ,rubber #cj ,rubber ,stamps #cj ,saw ,filing #cj ,saws1 ,management of #cj ,sheet-,metal ,works #ab1 #ac ,shop ,construction #be ,shop ,management #be ,shop ,practice #be ,shop ,tools #be ,sketching ,paper #ad ,soldering #g ,splices and ,rope ,work #bj ,steam ,engineering #cj1 #ca ,steam ,heating #ca1 #cb ,steel #cb ,storage ,batteries #e ,submarine ,chart #i ,switchboards #ad1 #af ,tapers #ba ,telegraphy1 ,wireless #ag ,telephone #af ,thread ,cutting #bf ,tool ,making #bd ,toy ,making #ae ,train ,rules #bc ,tractive ,power ,chart #i ,tractor1 ,gas #cc ,turbines #cc ,vacuum ,heating #cb ,valve ,setting #bb ,ventilation #ca ,watch ,making #cc ,waterproofing #ab ,welding with ,oxy-acetylene ,flame #e1 #cc ,wireless ,telegraphy #ag ,wiring #ad1 #ae ,wiring ,diagrams #ad ,any of these books promptly sent prepaid to any address in the world on receipt of price4 ,,how ,,to ,,remit--,by ,postal ,money ,order1 ,express ,money ,order1 ,bank ,draft or ,registered ,letter4 ,,automobiles ,,and ,,motorcycles ,the ,modern ,gasoline ,automobile--,its ,design1 ,construction1 and ,operation1 #aiah ,edition4 ,by ,,victor ,w4 ,,page1 ,m4,s4,a4,e4 ,this is the most complete1 practical and up-to-date treatise on gasoline automobiles and their component parts ever published4 ,in the new revised and enlarged #aiah edition1 all phases of automobile construction1 operation and maintenance are fully and completely described1 and in language anyone can understand4 ,every part of all types of automobiles1 from light cycle-cars to heavy motor trucks and tractors1 are described in a thorough manner1 not only the automobile1 but every item of it2 equipment1 accessories1 tools needed1 supplies and spare parts necessary for its upkeep1 are fully discussed4 ,it is clearly and concisely written by an expert familiar with every branch of the automobile industry and the originator of the practical system of self-education on technical subjects4 ,it is a liberal education in the automobile art1 useful to all who motor for either business or pleasure4 ,anyone reading the incomparable treatise is in touch with all improvements that have been made in motor-car construction4 ,all latest developments1 such as high speed aluminum motors and multiple valve and sleeve-valve engines1 are considered in detail4 ,the latest ignition1 carburetor and lubrication practice is outlined4 ,new forms of change speed gears1 and final power transmission systems1 and all latest chassis improvements are shown and described4 ,this book is used in all leading automobile schools and is conceded to be the ,,standard ,,treatise4 ,the chapter on ,starting and ,lighting ,systems has been greatly enlarged1 and many automobile engineering features that have long puzzled laymen are explained so clearly that the underlying principles can be understood by anyone4 ,this book was first published six years ago and so much new matter has been added that it is nearly twice1 its original size4 ,the only treatise covering various forms of war automobiles and recent developments in motor-truck design as well as pleasure cars4 ,this book is not too technical for the layman nor too elementary for the more expert4 ,it is an incomparable work of reference1 for home or school4 #a1jjj #fx#i pages1 nearly #a1jjj illustrations1 #ab folding plates4 ,cloth bound4 ,price #c4jj ,,what ,,is ,,said ,,of ,,this ,,book3 ,it is the best book on the ,automobile seen up to date4--,j4 ,h4 ,pile1 ,associate ,editor ,automobile ,trade ,journal4 ,every ,automobile ,owner has use for a book of this character4--,the ,tradesman4 ,this book is superior to any treatise heretofore published on the subject4--,the ,inventive ,age4 ,we know of no other volume that is so complete in all its departments1 and in which the wide field of automobile construction with its mechanical intricacies is so plainly handled1 both in the text and in the matter of illustrations4--,the ,motorist4 ,the book is very thorough1 a careful examination failing to disclose any point in connection with the automobile1 its care and repair1 to have been overlooked4--,iron ,age4 ,mr4 ,page has done a great work1 and benefit to the ,automobile ,field4--,w4 ,c4 ,hasford1 ,mgr4 ,y4 ,m4 ,c4 ,a4 ,automobile ,school1 ,boston1 ,mass4 ,it is just the kind of a book a motorist needs if he wants to understand his car4--,american ,thresherman4 ,the ,model ,t ,ford ,car1 ,its ,construction1 ,operation and ,repair4 ,by ,,victor ,w4 ,,page1 ,m4,s4,a4,e4 ,this is a complete instruction book4 ,all parts of the ,ford ,model ,t ,car are described and illustrated2 the construction is fully described and operating principles made clear to everyone4 ,every ,ford owner needs this practical book4 ,you don't have to guess about the construction or where the trouble is1 as it shows how to take all parts apart and how to locate and fix all faults4 ,the writer1 ,mr4 ,page1 has operated a ,ford car for many years and writes from actual knowledge4 ,among the contents are3 #a4 ,the ,ford ,car3 ,its ,parts and ,their ,functions4 #b4 ,the ,engine and ,auxiliary ,groups4 ,how the ,engine ,works--,the ,fuel ,supply ,system--,the ,carburetor--,making the ,ignition ,spark--,cooling and ,lubrication4 #c4 ,details of ,chassis4 ,change ,speed ,gear--,power ,transmission--,differential ,gear ,action--,steering ,gear--,front ,axle--,frame and ,springs--,brakes4 #d4 ,how to ,drive and ,care for the ,ford4 ,the ,control ,system ,explained--,starting the ,motor--,driving the ,car--,locating ,roadside ,troubles--,tire ,repairs--,oiling the ,chassis--,winter ,care of ,car4 #e4 ,systematic ,location of ,troubles and ,remedies4 ,faults in ,engine--,faults in ,carburetor--,ignition ,troubles--,cooling and ,lubrication ,system ,defects--,adjustment of ,transmission ,gear--,general ,chassis ,repairs4 #ie illustrations1 #cjj pages1 #b large folding plates4 ,price #a4jj ,how to ,run an ,automobile4 ,by ,,victor ,w4 ,,page1 ,m4,s4,a4,e4 ,this treatise gives concise instructions for starting and running all makes of gasoline automobiles1 how to care for them1 and gives distinctive features of control4 ,describes every step for shifting gears1 controlling engines1 etc4 ,among the chapters contained are3 ,i4--,automobile ,parts and ,their ,functions4 ,,ii4--,general ,starting and ,driving ,instructions4 ,,iii4--,typical #aiag ,control ,systems4 ,,iv4--,care of ,automobiles4 #agh pages4 #gb specially made illustrations4 ,price #a4jj ,automobile ,repairing ,made ,easy4 ,by ,,victor ,w4 ,,page1 ,m4,s4,a4,e4 ,a comprehensive1 practical exposition of every phase of modern automobile repairing practice4 ,outlines every process incidental to motor car restoration4 ,gives plans for workshop construction1 suggestions for equipment1 power needed1 machinery and tools necessary to carry on business successfully4 ,tells how to overhaul and repair all parts of all automobiles4 ,everything is explained so simply that motorists and students can acquire a full working knowledge of automobile repairing4 ,this work starts with the engine1 then considers carburetion1 ignition1 cooling and lubrication systems4 ,the clutch1 change speed gearing and transmission system are considered in detail4 ,contains instructions for repairing all types of axles1 steering gears and other chassis parts4 ,many tables1 short cuts in figuring and rules of practice are given for the mechanic4 ,explains fully valve and magneto timing1 tuning engines1 systematic location of trouble1 repair of ball and roller bearings1 shop kinks1 first aid to injured and a multitude of subjects of interest to all in the garage and repair business4 ,this book contains special instructions on electric starting1 lighting and ignition systems1 tire repairing and rebuilding1 autogenous welding1 brazing and soldering1 heat treatment of steel1 latest timing practice1 eight and twelve-cylinder motors1 etc4 #e-c_/dx#h4 ,cloth4 #a1jef pages1 #a1jjj illustrations1 #aa folding plates4 ,price #c4jj ,,what ,,is ,,said ,,of ,,this ,,book3 ',automobile ,repairing ,made ,easy' is the best book on the subject ,i have ever seen and the only book ,i ever saw that is of any value in a garage4--,fred ,jeffrey1 ,martinsburg1 ,neb4 ,i wish to thank you for sending me a copy of ',automobile ,repairing ,made ,easy4' ,i do not think it could be excelled4--,s4 ,w4 ,gisriel1 ,director of ,instruction1 ,y4 ,m4 ,c4 ,a41 ,philadelphia1 ,pa4 ,questions and ,answers ,relating to ,modern ,automobile ,construction1 ,driving and ,repair4 ,by ,,victor ,w4 ,,page1 ,m4,s4,a4,e4 ,a practical self-instructor for students1 mechanics and motorists1 consisting of thirty-seven lessons in the form of questions and answers1 written with special reference to the requirements of the non-technical reader desiring easily understood1 explanatory matter relating to all branches of automobiling4 ,the subject-matter is absolutely correct and explained in simple language4 ,if you can't answer all of the following questions1 you need this work4 ,the answers to these and over #b1jjj more are to be found in its pages4 ,give the name of all important parts of an automobile and describe their functions4 ,describe action of latest types of kerosene carburetors4 ,what is the difference between a double ignition system and a dual ignition system8 ,name parts of an induction coil4 ,how are valves timed8 ,what is an electric motor starter and how does it work8 ,what are advantages of worm drive gearing8 ,name all important types of ball and roller bearings4 ,what is a three-quarter floating axle8 ,what is a two-speed axle8 ,what is the ,vulcan electric gear shift8 ,name the causes of lost power in automobiles4 ,describe all noises due to deranged mechanism and give causes8 ,how can you adjust a carburetor by the color of the exhaust gases8 ,what causes popping in the carburetor8 ,what tools and supplies are needed to equip a car8 ,how do you drive various makes of cars8 ,what is a differential lock and where is it used8 ,name different systems of wire wheel construction1 etc41 etc4 ,a popular work at a popular price4 #e-a_/dx#g-a_/b4 ,cloth4 #fej pages1 #cej illustrations1 #c folding plates4 ,price #a4ej ,,what ,,is ,,said ,,of ,,this ,,book3 ,if you own a car--get this book4--,the ,glassworker4 ,mr4 ,page has the faculty of making difficult subjects plain and understandable4--,bristol ,press4 ,we can name no writer better qualified to prepare a book of instruction on automobiles than ,mr4 ,victor ,w4 ,page4--,scientific ,american4 ,the best automobile catechism that has appeared4--,automobile ,topics4 ,there are few men1 even with long experience1 who will not find this book useful4 ,great pains have been taken to make it accurate4 ,special recommendation must be given to the illustrations1 which have been made specially for the work4 ,such excellent books as this greatly assist in fully understanding your automobile4--,engineering ,news4 ,the ,automobilist's ,pocket ,companion and ,expense ,record4 ,arranged by ,,victor ,w4 ,,page1 ,m4,s4,a4,e4 ,this book is not only valuable as a convenient cost record but contains much information of value to motorists4 ,includes a condensed digest of auto laws of all ,states1 a lubrication schedule1 hints for care of storage battery and care of tires1 location of road troubles1 anti-freezing solutions1 horse-power table1 driving hints and many useful tables and recipes of interest to all motorists4 ,not a technical book in any sense of the word1 just a collection of practical facts in simple language for the everyday motorist4 ,price #a4jj ,modern ,starting1 ,lighting and ,ignition ,systems4 ,by ,,victor ,w4 ,,page1 ,m4,e4 ,this practical volume has been written with special reference to the requirements of the non-technical reader desiring easily understood1 explanatory matter1 relating to all types of automobile ignition1 starting and lighting systems4 ,it can be understood by anyone1 even without electrical knowledge1 because elementary electrical principles are considered before any attempt is made to discuss features of the various systems4 ,these basic principles are clearly stated and illustrated with simple diagrams4 ,all the leading systems of starting1 lighting and ignition have been described and illustrated with the co-operation of the experts employed by the manufacturers4 ,wiring diagrams are shown in both technical and non-technical forms4 ,all symbols are fully explained4 ,it is a comprehensive review of modern starting and ignition system practice1 and includes a complete exposition of storage battery construction1 care and repair4 ,all types of starting motors1 generators1 magnetos1 and all ignition or lighting system-units are fully explained4 ,every person in the automobile business needs this volume4 ,among some of the subjects treated are3 ,i4--,elementary ,electricity2 ,current ,production2 ,flow2 ,circuits2 ,measurements2 ,definitions2 ,magnetism2 ,battery ,action2 ,generator ,action4 ,,ii4--,battery ,ignition ,systems4 ,,iii4--,magneto ,ignition ,systems4 ,,iv4--,elementary ,exposition of ,starting ,system ,principles4 ,v4--,typical ,starting and ,lighting ,systems2 ,practical ,application2 ,wiring ,diagrams2 ,auto-lite1 ,bijur1 ,delco1 ,dyneto-,entz1 ,gray and ,davis1 ,remy1 ,u4 ,s4 ,l41 ,westinghouse1 ,bosch-,rushmore1 ,genemotor1 ,north-,east1 etc4 ,,vi4--,locating and ,repairing ,troubles in ,starting and ,lighting ,systems4 ,,vii4--,auxiliary4 ,electric ,systems2 ,gear-shifting by ,electricity2 ,warning ,signals2 ,electric ,brake2 ,entz-,transmission1 ,wagner-,saxon ,circuits1 ,wagner-,studebaker ,circuits4 #e-a_/dx#g-a_/b4 ,cloth4 #ecj pages1 #big illustrations1 #c folding plates4 ,price #a4ej ,automobile ,welding ,with the ,oxy-,acetylene ,flame4 ,by ,m4 ,,keith ,,dunham4 ,this is the only complete book on the why and how of ,welding with the ,oxy-,acetylene ,flame1 and from its pages one can gain information so that he can weld anything that comes along4 ,no one can afford to be without this concise book1 as it first explains the apparatus to be used1 and then covers in detail the actual welding of all automobile parts4 ,the welding of aluminum1 cast iron1 steel1 copper1 brass and malleable iron is clearly explained1 as well as the proper way to burn the carbon out of the combustion head of the motor4 ,among the contents are3 ,chapter ,i4--,apparatus ,knowledge4 ,chapter ,,ii4--,shop ,equipment and ,initial ,procedure4 ,chapter ,,iii4--,cast ,iron4 ,chapter ,,iv4--,aluminum4 ,chapter ,v4--,steel4 ,chapter ,,vi4--,malleable ,iron1 ,copper1 ,brass1 ,bronze4 ,chapter ,,vii4--,carbon ,burning and other ,uses of ,oxygen and ,acetylene4 ,chapter ,,viii4--,how to ,figure ,cost of ,welding4 #afg pages1 fully illustrated4 ,price #a4jj ,storage ,batteries ,simplified4 ,by ,,victor ,w4 ,,page1 ,m4,s4,a4,e4 ,a comprehensive treatise devoted entirely to secondary batteries and their maintenance1 repair and use4 ,this is the most up-to-date book on this subject4 ,describes fully the ,exide1 ,edison1 ,gould1 ,willard1 ,u4 ,s4 ,l4 and other storage battery forms in the types best suited for automobile1 stationary and marine work4 ,nothing of importance has been omitted that the reader should know about the practical operation and care of storage batteries4 ,no details have been slighted4 ,the instructions for charging and care have been made as simple as possible4 ,brief ,synopsis of ,chapters3 ,chapter ,i4--,storage ,battery ,development2 ,types of ,storage ,batteries2 ,lead ,plate ,types2 ,the ,edison ,cell4 ,chapter ,,ii4--,storage ,battery ,construction2 ,plates and ,girds2 ,plante ,plates2 ,faure ,plates2 ,non-,lead ,plates2 ,commercial ,battery ,designs4 ,chapter ,,iii4--,charging ,methods2 ,rectifiers2 ,converters2 ,rheostats2 ,rules for ,charging4 ,chapter ,,iv4--,battery ,repairs and ,maintenance4 ,chapter ,v4--,industrial ,application of ,storage ,batteries2 ,glossary of ,storage ,battery ,terms4 #bjh ,pages4 ,very ,fully ,illustrated4 ,price #a4ej net4 ,motorcycles1 ,side ,cars and ,cyclecars2 their ,construction1 ,management and ,repair4 ,by ,,victor ,w4 ,,page1 ,m4,s4,a4,e4 ,the only complete work published for the motorcyclist and cyclecarist4 ,describes fully all leading types of machines1 their design1 construction1 maintenance1 operation and repair4 ,this treatise outlines fully the operation of two- and four-cycle power plants and all ignition1 carburetion and lubrication systems in detail4 ,describes all representative types of free engine clutches1 variable speed gears and power transmission systems4 ,gives complete instructions for operating and repairing all types4 ,considers fully electric self-starting and lighting systems1 all types of spring frames and spring forks and shows leading control methods4 ,for those desiring technical information a complete series of tables and many formulae to assist in designing are included4 ,the work tells how to figure power needed to climb grades1 overcome air resistance and attain high speeds4 ,it shows how to select gear ratios for various weights and powers1 how to figure braking efficiency required1 gives sizes of belts and chains to transmit power safely1 and shows how to design sprockets1 belt pulleys1 etc4 ,this work also includes complete formulae for figuring horse-power1 shows how dynamometer tests are made1 defines relative efficiency of air and water-cooled engines1 plain and anti-friction bearings and many other data of a practical1 helpful1 engineering nature4 ,remember that you get this information in addition to the practical description and instructions which alone are worth several times the price of the book4 #eej pages4 #cej specially made illustrations1 #e folding plates4 ,cloth4 ,price #a4ej ,,what ,,is ,,said ,,of ,,this ,,book3 ,here is a book that should be in the cycle repairer's kit4--,american ,blacksmith4 ,the best way for any rider to thoroughly understand his machine1 is to get a copy of this book2 it is worth many times its price4--,pacific ,motorcyclist4 ,,automobile ,,and ,,motorcycle ,,charts ,chart4 ,location of ,gasoline ,engine ,troubles ,made ,easy--,a ,chart ,showing ,sectional ,view of ,gasoline ,engine4 ,compiled by ,,victor ,w4 ,,page1 ,m4,s4,a4,e4 ,it shows clearly all parts of a typical four-cylinder gasoline engine of the four-cycle type4 ,it outlines distinctly all parts liable to give trouble and also details the derangements apt to interfere with smooth engine operation4 ,valuable to students1 motorists1 mechanics1 repairmen1 garagemen1 automobile salesmen1 chauffeurs1 motorboat owners1 motor-truck and tractor drivers1 aviators1 motor-cyclists1 and all others who have to do with gasoline power plants4 ,it simplifies location of all engine troubles1 and while it will prove invaluable to the novice1 it can be used to advantage by the more expert4 ,it should be on the walls of every public and private garage1 automobile repair shop1 club house or school4 ,it can be carried in the automobile or pocket with ease1 and will insure against loss of time when engine trouble manifests itself4 ,this sectional view of engine is a complete review of all motor troubles4 ,it is prepared by a practical motorist for all who motor4 ,more information for the money than ever before offered4 ,no details omitted4 ,size #bex#ch inches4 ,securely mailed on receipt of #be ,cents ,chart4 ,location of ,ford ,engine ,troubles ,made ,easy4 ,compiled by ,,victor ,w4 ,,page1 ,m4,s4,a4,e4 ,this shows clear sectional views depicting all portions of the ,ford power plant and auxiliary groups4 ,it outlines clearly all parts of the engine1 fuel supply system1 ignition group and cooling system1 that are apt to give trouble1 detailing all derangements that are liable to make an engine lose power1 start hard or work irregularly4 ,this chart is valuable to students1 owners1 and drivers1 as it simplifies location of all engine faults4 ,of great advantage as an instructor for the novice1 it can be used equally well by the more expert as a work of reference and review4 ,it can be carried in the tool-box or pocket with ease and will save its cost in labor eliminated the first time engine trouble manifests itself4 ,prepared with special reference to the average man's needs and is a practical review of all motor troubles because it is based on the actual experience of an automobile engineer-mechanic with the mechanism the chart describes4 ,it enables the non-technical owner or operator of a ,ford car to locate engine derangements by systematic search1 guided by easily recognized symptoms instead of by guesswork4 ,it makes the average owner independent of the roadside repair shop when touring4 ,must be seen to be appreciated4 ,size #bex#ch inches4 ,printed on heavy bond paper4 ,price #be cents ,chart4 ,lubrication of the ,motor ,car ,chassis4 ,compiled by ,,victor ,w4 ,,page1 ,m4,s4,a4,e4 ,this chart presents the plan view of a typical six-cylinder chassis of standard design and all parts are clearly indicated that demand oil1 also the frequency with which they must be lubricated and the kind of oil to use4 ,a practical chart for all interested in motor-car maintenance4 ,size #bdx#ch inches4 ,price #be cents ,chart4 ,location of ,carburetion ,troubles ,made ,easy4 ,compiled by ,,victor ,w4 ,,page1 ,m4,s4,a4,e4 ,this chart shows all parts of a typical pressure feed fuel supply system and gives causes of trouble1 how to locate defects and means of remedying them4 ,size #bdx#ch inches4 ,price #be cents ,chart4 ,location of ,ignition ,system ,troubles ,made ,easy4 ,compiled by ,,victor ,w4 ,,page1 ,m4,s4,a4,e4 ,in this diagram all parts of a typical double ignition system using battery and magneto current are shown1 and suggestions are given for readily finding ignition troubles and eliminating them when found4 ,size #bdx#ch inches4 ,price #be cents ,chart4 ,location of ,cooling and ,lubrication ,system ,faults4 ,compiled by ,,victor ,w4 ,,page1 ,m4,s4,a4,e4 ,this composite diagram shows a typical automobile power plant using pump circulated water-cooling system and the most popular lubrication method4 ,gives suggestions for curing all overheating and loss of power faults due to faulty action of the oiling or cooling group4 ,size #bdx#ch inches4 ,price #be cents ,chart4 ,motorcycle ,troubles ,made ,easy4 ,compiled by ,,victor ,w ,,page1 ,m4,s4,a4,e4 ,a chart showing sectional view of a single-cylinder gasoline engine4 ,this chart simplifies location of all power-plant troubles4 ,a single-cylinder motor is shown for simplicity4 ,it outlines distinctly all parts liable to give trouble and also details the derangements apt to interfere with smooth engine operation4 ,this chart will prove of value to all who have to do with the operation1 repair or sale of motorcycles4 ,no details omitted4 ,size #cjx#bj inches ,price #be cents ,,aviation ,aviation ,engines1 their ,design1 ,construction1 ,operation and ,repair4 ,by ,lieut4 ,,victor ,w4 ,,page1 ,aviation ,section1 ,s4,c4,u4,s4,r4 ,a practical work containing valuable instructions for aviation students1 mechanicians1 squadron engineering officers and all interested in the construction and upkeep of airplane power plants4 ,the rapidly increasing interest in the study of aviation1 and especially of the highly developed internal combustion engines that make mechanical flight possible1 has created a demand for a text-book suitable for schools and home study that will clearly and concisely explain the workings of the various aircraft engines of foreign and domestic manufacture4 ,this treatise1 written by a recognized authority on all of the practical aspects of internal combustion engine construction1 maintenance and repair fills the need as no other book does4 ,the matter is logically arranged2 all descriptive matter is simply expressed and copiously illustrated so that anyone can understand airplane engine operation and repair even if without previous mechanical training4 ,this work is invaluable for anyone desiring to become an aviator or aviation mechanician4 ,the latest rotary types1 such as the ,gnome1 ,monosoupape1 and ,le ,rhone1 are fully explained1 as well as the recently developed ,vee and radial types4 ,the subjects of carburetion1 ignition1 cooling and lubrication also are covered in a thorough manner4 ,the chapters on repair and maintenance are distinctive and found in no other book on this subject4 ,invaluable to the student1 mechanic and soldier wishing to enter the aviation service4 ,not a technical book1 but a practical1 easily understood work of reference for all interested in aeronautical science4 #egf octavo pages4 #bec specially made engravings4 ,price #c4jj net ,,glossary ,,of ,,aviation ,,terms ,termes ,d',aviation1 ,english-,french1 ,french-,english4 ,compiled by ,lieuts4 ,,victor ,w4 ,,page1 ,a4,s41 ,s4,c4,u4,s4,r41 and ,,paul ,,montariol of the ,french ,flying ,corps1 on duty on ,signal ,corps ,aviation ,school1 ,mineola1 ,l4 ,i4 ,a complete1 well illustrated volume intended to facilitate conversation between ,english-speaking and ,french aviators4 ,a very valuable book for all who are about to leave for duty overseas4 ,approved for publication by ,major ,w4 ,g4 ,kilner1 ,s4,c41 ,u4,s4,c4,o4 ,signal ,corps ,aviation ,school4 ,hazelhurst ,field1 ,mineola1 ,l4 ,i4 ,this book should be in every ,aviator's and ,mechanic's ,kit for ready reference4 #abh pages4 ,fully illustrated with detailed engravings4 ,price #a4jj ,aviation ,chart4 ,location of ,airplane ,power ,plant ,troubles ,made ,easy4 ,by ,lieut4 ,,victor ,w4 ,,page1 ,a4,s41 ,s4,c4,u4,s4,r4 ,a large chart outlining all parts of a typical airplane power plant1 showing the points where trouble is apt to occur and suggesting remedies for the common defects4 ,intended especially for ,aviators and ,aviation ,mechanics on ,school and ,field ,duty4 ,price #ej cents ,,brazing ,,and ,,soldering ,brazing and ,soldering4 ,by ,,james ,f4 ,,hobart4 ,the only book that shows you just how to handle any job of brazing or soldering that comes along2 it tells you what mixture to use1 how to make a furnace if you need one4 ,full of valuable kinks4 ,the fifth edition of this book has just been published1 and to it much new matter and a large number of tested formulae for all kinds of solders and fluxes have been added4 ,illustrated4 ,price #be cents ,,charts ,aviation ,chart4 ,location of ,airplane ,power ,plant ,troubles ,made ,easy4 ,by ,lieut4 ,,victor ,w4 ,,page1 ,a4,s41 ,s4,c4,u4,s4,r4 ,a large chart outlining all parts of a typical airplane power plant1 showing the points where trouble is apt to occur and suggesting remedies for the common defects4 ,intended especially for ,aviators and ,aviation ,mechanics on ,school and ,field ,duty4 ,price #ej cents ,gasoline ,engine ,troubles ,made ,easy--,a ,chart ,showing ,sectional ,view of ,gasoline ,engine4 ,compiled by ,lieut4 ,,victor ,w4 ,,page1 ,a4,s41 ,s4,c4,u4,s4,r4 ,it shows clearly all parts of a typical four-cylinder gasoline engine of the four-cycle type4 ,it outlines distinctly all parts liable to give trouble and also details the derangements apt to interfere with smooth engine operation4 ,valuable to students1 motorists1 mechanics1 repairmen1 garagemen1 automobile salesmen1 chauffeurs1 motor-boat owners1 motor-truck and tractor drivers1 aviators1 motor-cyclists1 and all others who have to do with gasoline power plants4 ,it simplifies location of all engine troubles1 and while it will prove invaluable to the novice1 it can be used to advantage by the more expert4 ,it should be on the walls of every public and private garage1 automobile repair shop1 club house or school4 ,it can be carried in the automobile or pocket with ease and will insure against loss of time when engine trouble manifests itself4 ,this sectional view of engine is a complete review of all motor troubles4 ,it is prepared by a practical motorist for all who motor4 ,no details omitted4 ,size #bex#ch inches4 ,price #be cents ,lubrication of the ,motor ,car ,chassis4 ,this chart presents the plan view of a typical six-cylinder chassis of standard design and all parts are clearly indicated that demand oil1 also the frequency with which they must be lubricated and the kind of oil to use4 ,a practical chart for all interested in motor-car maintenance4 ,size #bdx#ch inches4 ,price #be cents ,location of ,carburetion ,troubles ,made ,easy4 ,this chart shows all parts of a typical pressure feed fuel supply system and gives causes of trouble1 how to locate defects and means of remedying them4 ,size #bdx#ch inches4 ,price #be cents ,location of ,ignition ,system ,troubles ,made ,easy4 ,in this chart all parts of a typical double ignition system using battery and magneto current are shown and suggestions are given for readily finding ignition troubles and eliminating them when found4 ,size #bdx#ch inches4 ,price #be cents ,location of ,cooling and ,lubrication ,system ,faults4 ,this composite chart shows a typical automobile power plant using pump circulated water-cooling system and the most popular lubrication method4 ,gives suggestions for curing all overheating and loss of power faults due to faulty action of the oiling or cooling group4 ,size #bdx#ch inches4 ,price #be ,cents ,motorcycle ,troubles ,made ,easy--,a ,chart ,showing ,sectional ,view of ,single-,cylinder ,gasoline ,engine4 ,compiled by ,,victor ,w4 ,,page1 ,m4,s4,a4,e4 ,this chart simplifies location of all power-plant troubles1 and will prove invaluable to all who have to do with the operation1 repair or sale of motorcycles4 ,no details omitted4 ,size #bex#ch inches4 ,price #be cents ,location of ,ford ,engine ,troubles ,made ,easy4 ,compiled by ,,victor ,w4 ,,page1 ,m4,s4,a4,e4 ,this shows clear sectional views depicting all portions of the ,ford power plant and auxiliary groups4 ,it outlines clearly all parts of the engine1 fuel supply system1 ignition group and cooling system1 that are apt to give trouble1 detailing all derangements that are liable to make an engine lose power1 start hard or work irregularly4 ,this chart is valuable to students1 owners1 and drivers1 as it simplifies location of all engine faults4 ,of great advantage as an instructor for the novice1 it can be used equally well by the more expert as a work of reference and review4 ,it can be carried in the toolbox or pocket with ease and will save its cost in labor eliminated the first time engine trouble manifests itself4 ,prepared with special reference to the average man's needs and is a practical review of all motor troubles because it is based on the actual experience of an automobile engineer-mechanic with the mechanism the chart describes4 ,it enables the non-technical owner or operator of a ,ford car to locate engine derangements by systematic search1 guided by easily recognized symptoms instead of by guesswork4 ,it makes the average owner independent of the roadside repair shop when touring4 ,must be seen to be appreciated4 ,size #bex#ch inches4 ,printed on heavy bond paper4 ,price #be cents ,modern ,submarine ,chart--with ,two ,hundred ,parts ,numbered and ,named4 ,a cross-section view1 showing clearly and distinctly all the interior of a ,submarine of the latest type4 ,you get more information from this chart1 about the construction and operation of a ,submarine1 than in any other way4 ,no details omitted--everything is accurate and to scale4 ,it is absolutely correct in every detail1 having been approved by ,naval ,engineers4 ,all the machinery and devices fitted in a modern ,submarine ,boat are shown1 and to make the engraving more readily understood all the features are shown in operative form1 with ,officers and ,men in the act of performing the duties assigned to them in service conditions4 ,this ,,chart ,,is ,,really ,,an ,,encyclopedia ,,of ,a ,,submarine4 ,it is educational and worth many times its cost4 ,mailed in a ,tube for #be ,cents ,box ,car ,chart4 ,a chart showing the anatomy of a box car1 having every part of the car numbered and its proper name given in a reference list4 ,price #be ,cents ,gondola ,car ,chart4 ,a chart showing the anatomy of a gondola car1 having every part of the car numbered and its proper reference name given in a reference list4 ,price #be ,cents ,passenger-,car ,chart4 ,a chart showing the anatomy of a passenger-car1 having every part of the car numbered and its proper name given in a reference list #be ,cents ,steel ,hopper ,bottom ,coal ,car4 ,a chart showing the anatomy of a steel ,hopper ,bottom ,coal ,car1 having every part of the car numbered and its proper name given in a reference list4 ,price #be ,cents ,tractive ,power ,chart4 ,a chart whereby you can find the tractive power or drawbar pull of any locomotive without making a figure4 ,shows what cylinders are equal1 how driving wheels and steam pressure affect the power4 ,what sized engine you need to exert a given drawbar pull or anything you desire in this line4 ,price #ej ,cents ,horse-,power ,chart4 ,shows the horse-power of any stationary engine without calculation4 ,no matter what the cylinder diameter of stroke1 the steam pressure of cut-off1 the revolutions1 or whether condensing or non-condensing1 it's all there4 ,easy to use1 accurate1 and saves time and calculations4 ,especially useful to engineers and designers4 ,price #ej ,cents ,boiler ,room ,chart4 ,by ,,geo4 ,l4 ,,fowler4 ,a chart--size #adx#bh inches--showing in isometric perspective the mechanisms belonging in a modern boiler room4 ,the various parts are shown broken or removed1 so that the internal construction is fully illustrated4 ,each part is given a reference number1 and these1 with the corresponding name1 are given in a glossary printed at the sides4 ,this chart is really a dictionary of the boiler room--the names of more than #bjj parts being given4 ,price #be ,cents ,,coke ,modern ,coking ,practice1 ,including ,analysis of ,materials and ,products4 ,by ,j4 ,e4 ,,christopher and ,t4 ,h4 ,,byrom4 ,this1 the standard work on the subject1 has just been revised4 ,it is a practical work for those engaged in ,coke manufacture and the recovery of ,by-products4 ,fully illustrated with folding plates4 ,it has been the aim of the authors1 in preparing this book1 to produce one which shall be of use and benefit to those who are associated with1 or interested in1 the modern developments of the industry4 ,among the ,chapters contained in ,volume ,i are3 ,introduction2 ,classification of ,fuels2 ,impurities of ,coals2 ,coal ,washing2 ,sampling and ,valuation of ,coals1 etc42 ,power of ,fuels2 ,history of ,coke ,manufacture2 ,developments in the ,coke ,oven ,design2 ,recent ,types of ,coke ,ovens2 ,mechanical ,appliances at ,coke ,ovens2 ,chemical and ,physical ,examination of ,coke4 ,volume ,,ii covers fully the subject of ,by-,products4 ,price1 per volume #c4jj net ,,compressed ,,air ,compressed ,air in ,all ,its ,applications4 ,by ,,gardner ,d4 ,,hiscox4 ,this is the most complete book on the subject of ,air that has ever been issued1 and its thirty-five chapters include about every phase of the subject one can think of4 ,it may be called an encyclopedia of compressed air4 ,it is written by an expert1 who1 in its #ffe pages1 has dealt with the subject in a comprehensive manner1 no phase of it being omitted4 ,includes the physical properties of air from a vacuum to its highest pressure1 its thermodynamics1 compression1 transmission and uses as a motive power1 in the ,operation of ,stationary and ,portable ,machinery1 in ,mining1 ,air ,tools1 ,air ,lifts1 ,pumping of ,water1 ,acids1 and ,oils2 the ,air ,blast for ,cleaning and ,painting the ,sand ,blast and its ,work1 and the ,numerous ,appliances in which ,compressed ,air is a ,most ,convenient and ,economical ,transmitter of ,power for ,mechanical ,work1 ,railway ,propulsion1 ,refrigeration1 and the ,various ,uses to which ,compressed ,air has been applied4 ,includes forty-four tables of the physical properties of air1 its compression1 expansion1 and volumes required for various kinds of work1 and a list of patents on compressed air from #ahge to date4 ,over #ejj illustrations1 #eth ,edition1 revised and enlarged4 ,cloth bound4 ,price #e4jj ,half ,morocco4 ,price #f4ej ,,concrete ,concrete ,workers' ,reference ,books4 ,a ,series of ,popular ,handbooks for ,concrete ,users4 ,prepared by ,a4 ,a4 ,,houghton #ej cents ,the author1 in preparing this ,series1 has not only treated on the usual types of construction1 but explains and illustrates molds and systems that are not patented1 but which are equal in value and often superior to those restricted by patents4 ,these molds are very easily and cheaply constructed and embody simplicity1 rapidity of operation1 and the most successful results in the molded concrete4 ,each of these books is fully illustrated1 and the subjects are exhaustively treated in plain ,english4 ,concrete ,wall ,forms4 ,by ,a4 ,a4 ,,houghton4 ,a new automatic wall clamp is illustrated with working drawings4 ,other types of wall forms1 clamps1 separators1 etc41 are also illustrated and explained4 7,no4 #a of ,series7 ,price #ej cents ,concrete ,floors and ,sidewalks4 ,by ,a4 ,a4 ,,houghton4 ,the molds for molding squares1 hexagonal and many other styles of mosaic floor and sidewalk blocks are fully illustrated and explained4 7,no4 #b of ,series7 ,price #ej cents ,practical ,concrete ,silo ,construction4 ,by ,a4 ,a4 ,,houghton4 ,complete working drawings and specifications are given for several styles of concrete silos1 with illustrations of molds for monolithic and block silos4 ,the tables1 data1 and information presented in this book are of the utmost value in planning and constructing all forms of concrete silos4 7,no4 #c of ,series7 ,price #ej cents ,molding ,concrete ,chimneys1 ,slate and ,hoof ,tiles4 ,by ,a4 ,a4 ,,houghton4 ,the manufacture of all types of concrete slate and roof tile is fully treated4 ,valuable data on all forms of reinforced concrete roofs are contained within its pages4 ,the construction of concrete chimneys by block and monolithic systems is fully illustrated and described4 ,a number of ornamental designs of chimney construction with molds are shown in this valuable treatise4 7,no4 #d of ,series47 ,price #ej cents ,molding and ,curing ,ornamental ,concrete4 ,by ,a4 ,a4 ,,houghton4 ,the proper proportions of cement and aggregates for various finishes1 also the method of thoroughly mixing and placing in the molds1 are fully treated4 ,an exhaustive treatise on this subject that every concrete worker will find of daily use and value4 7,no4 #e of ,series47 ,price #ej cents ,concrete ,monuments1 ,mausoleums and ,burial ,vaults4 ,by ,a4 ,a4 ,,houghton4 ,the molding of concrete monuments to imitate the most expensive cut stone is explained in this treatise with working drawings of easily built molds4 ,cutting inscriptions and designs are also fully treated4 7,no4 #f of ,series47 ,price #ej cents ,molding ,concrete ,bathtubs1 ,aquariums and ,natatoriums4 ,by ,a4 ,a4 ,,houghton4 ,simple molds and instruction are given for molding many styles of concrete bathtubs1 swimming-pools1 etc4 ,these molds are easily built and permit rapid and successful work4 7,no4 #g of ,series47 ,price #ej cents ,concrete ,bridges1 ,culverts and ,sewers4 ,by ,a4 ,a4 ,,houghton4 ,a number of ornamental concrete bridges with illustrations of molds are given4 ,a collapsible center or core for bridges1 culverts and sewers is fully illustrated with detailed instructions for building4 7,no4 #h of ,series47 ,price #ej cents ,constructing ,concrete ,porches4 ,by ,a4 ,a4 ,,houghton4 ,a number of designs with working drawings of molds are fully explained so any one can easily construct different styles of ornamental concrete porches without the purchase of expensive molds4 7,no4 #i of ,series47 ,price #ej cents ,molding ,concrete ,flower-,pots1 ,boxes1 ,jardinieres1 ,etc4 ,by ,a4 ,a4 ,,houghton4 ,the molds for producing many original designs of flower-pots1 urns1 flower-boxes1 jardinieres1 etc41 are fully illustrated and explained1 so the worker can easily construct and operate same4 7,no4 #aj of ,series47 ,price #ej cents ,molding ,concrete ,fountains and ,lawn ,ornaments4 ,by ,a4 ,a4 ,,houghton4 ,the molding of a number of designs of lawn seats1 curbing1 hitching posts1 pergolas1 sun dials and other forms of ornamental concrete for the ornamentation of lawns and gardens1 is fully illustrated and described4 7,no4 #aa of ,series47 ,price #ej cents ,concrete from ,sand ,molds4 ,by ,a4 ,a4 ,,houghton4 ,a ,practical ,work treating on a process which has heretofore been held as a trade secret by the few who possessed it1 and which will successfully mold every and any class of ornamental concrete work4 ,the process of molding concrete with sand molds is of the utmost practical value1 possessing the manifold advantages of a low cost of molds1 the ease and rapidity of operation1 perfect details to all ornamental designs1 density and increased strength of the concrete1 perfect curing of the work without attention and the easy removal of the molds regardless of any undercutting the design may have4 #aib pages4 ,fully illustrated ,price #b4jj ,ornamental ,concrete without ,molds4 ,by ,a4 ,a4 ,,houghton4 ,the process for making ornamental concrete without molds has long been held as a secret1 and now1 for the first time1 this process is given to the public4 ,the book reveals the secret and is the only book published which explains a simple1 practical method whereby the concrete worker is enabled1 by employing wood and metal templates of different designs1 to mold or model in concrete any ,cornice1 ,archivolt1 ,column1 ,pedestal1 ,base ,cap1 ,urn or ,pier in a monolithic form--right upon the job4 ,these may be molded in units or blocks and then built up to suit the specifications demanded4 ,this work is fully illustrated1 with detailed engravings4 ,price #b4jj ,concrete for the ,farm and in the ,shop4 ,by ,h4 ,,colin ,,campbell1 ,c4,e41 ,e4,m4 ,concrete for the ,farm and in the ,shop is a new book from cover to cover1 illustrating and describing in plain1 simple language many of the numerous applications of concrete within the range of the home worker4 ,among the subjects treated are3 ,principles of ,reinforcing2 ,methods of ,protecting ,concrete so as to ,insure ,proper ,hardening2 ,home-made ,mixers2 ,mixing by ,hand and ,machine2 ,form ,construction1 ,described and ,illustrated by ,drawings and ,photographs2 ,construction of ,concrete ,walls and ,fences2 ,concrete ,fence ,posts2 ,concrete ,gate ,posts2 ,corner ,posts2 ,clothes ,line ,posts2 ,grape ,arbor ,posts2 ,tanks2 ,troughs2 ,cisterns2 ,hog ,wallows2 ,feeding ,floors and ,barnyard ,pavements2 ,foundations2 ,well ,curbs and ,platforms2 ,indoor ,floors2 ,sidewalks2 ,steps2 ,concrete ,hotbeds and ,cold ,frames2 ,concrete ,slab ,roofs2 ,walls for ,buildings2 ,repairing ,leaks in ,tanks and ,cisterns2 and all topics associated with these subjects as bearing upon securing the best results from concrete are dwelt upon at sufficient length in plain every-day ,english so that the inexperienced person desiring to undertake a piece of concrete construction can1 by following the directions set forth in this book1 secure #ajj per cent4 success every time4 ,a number of convenient and practical tables for estimating quantities1 and some practical examples1 are also given4 7#ex#g47 #adi pages4 #ea illustrations4 ,price #ge cents ,popular ,handbook for ,cement and ,concrete ,users4 ,by ,,myron ,h4 ,,lewis4 ,this is a concise treatise of the principles and methods employed in the manufacture and use of cement in all classes of modern works4 ,the author has brought together in this work all the salient matter of interest to the user of concrete and its many diversified products4 ,the matter is presented in logical and systematic order1 clearly written1 fully illustrated and free from involved mathematics4 ,everything of value to the concrete user is given1 including kinds of cement employed in construction1 concrete architecture1 inspection and testing1 waterproofing1 coloring and painting1 rules1 tables1 working and cost data4 ,the book comprises thirty-three chapters1 as follow3 ,introductory4 ,kinds of ,cement and ,how ,they are ,made4 ,properties4 ,testing and ,requirements of ,hydraulic ,cement4 ,concrete and ,its ,properties4 ,sand1 ,broken ,stone and ,gravel for ,concrete4 ,how to ,proportion the ,materials4 ,how to ,mix and ,place ,concrete4 ,forms of ,concrete ,construction4 ,the ,architectural and ,artistic ,possibilities of ,concrete4 ,concrete ,residences4 ,mortars1 ,plasters and ,stucco1 and ,how to ,use ,them4 ,the ,artistic ,treatment of ,concrete ,surfaces4 ,concrete ,building ,blocks4 ,the ,making of ,ornamental ,concrete4 ,concrete ,pipes1 ,fences1 ,posts1 etc4 ,essential ,features and ,advantages of ,reenforced ,concrete4 ,how to ,design ,reenforced ,concrete ,beams1 ,slabs and ,columns4 ,explanations of the ,methods and ,principles in ,designing ,reenforced ,concrete1 ,beams and ,slabs4 ,systems of ,reenforcement ,employed4 ,reenforced ,concrete in ,factory and ,general ,building ,construction4 ,concrete in ,foundation ,work4 ,concrete ,retaining ,walls1 ,abutments and ,bulkheads4 ,concrete ,arches and ,arch ,bridges4 ,concrete ,beam and ,girder ,bridges4 ,concrete in ,sewerage and ,draining ,works4 ,concrete ,tanks1 ,dams and ,reservoirs4 ,concrete ,sidewalks1 ,curbs and ,pavements4 ,concrete in ,railroad ,construction4 ,the ,utility of ,concrete on the ,farm4 ,the ,waterproofing of ,concrete ,structures4 ,grout of ,liquid ,concrete and ,its ,use4 ,inspection of ,concrete ,work4 ,cost of ,concrete ,work4 ,some of the special features of the book are3 #a4--,the ,attention ,paid to the ,artistic and ,architectural ,side of ,concrete ,work4 #b4--,the ,authoritative ,treatment of the ,problem of ,waterproofing ,concrete4 #c4--;,an ,excellent ,summary of the ,rules to be ,followed in ,concrete ,construction4 #d4--,the ,valuable ,cost ,data and ,useful ,tables given4 ,a valuable ,addition to the ,library of ,every ,cement and ,concrete ,user4 ,price #b4ej ,,what ,,is ,,said ,,of ,,this ,,book3 ,the field of ,concrete ,construction is well covered and the matter contained is well within the understanding of any person4--,engineering-,contracting4 ,should be on the bookshelves of every contractor1 engineer1 and architect in the land4--,national ,builder4 ,waterproofing ,concrete4 ,by ,,myron ,h4 ,,lewis4 ,modern ,methods of ,waterproofing ,concrete and ,other ,structures4 ,a condensed statement of the ,principles1 ,rules1 and ,precautions to be ,observed in ,waterproofing and ,dampproofing ,structures and ,structural ,materials4 ,paper binding4 ,illustrated4 ,price #ej cents ,,dictionaries ,aviation ,terms1 ,termes ,d',aviation1 ,english-,french1 ,french-,english4 ,compiled by ,lieuts4 ,,victor ,w4 ,,page1 ,a4,s41 ,s4,c4,u4,s4,r41 and ,,paul ,,montariol1 of the ,french ,flying ,corps1 on duty on ,signal ,corps ,aviation ,school1 ,mineola1 ,l4 ,i4 ,the lists contained are confined to essentials1 and special folding plates are included to show all important airplane parts4 ,the lists are divided in four sections as follows3 #a4--;,flying ,field ,terms4 #b4--,the ,airplane4 #c4--,the ,engine4 #d4--,tools and ,shop ,terms4 ,a complete1 well illustrated volume intended to facilitate conversation between ,english-speaking and ,french aviators4 ,a very valuable book for all who are about to leave for duty overseas4 ,approved for publication by ,major ,w4 ,g4 ,kilner1 ,s4,c41 ,u4,s4,c4,o4 ,signal ,corps ,aviation ,school1 ,hazelhurst ,field1 ,mineola1 ,l4 ,i4 ,this book should be in every ,aviator's and ,mechanic's ,kit for ready reference4 #abh pages1 fully illustrated1 with detailed engravings4 ,price #a4jj ,standard ,electrical ,dictionary4 ,by ,t4 ,o',,conor ,,sloane4 ,an indispensable work to all interested in electrical science4 ,suitable alike for the student and professional4 ,a practical handbook of reference containing definitions of about #e1jjj distinct words1 terms and phrases4 ,the definitions are terse and concise2 and include every term used in electrical science4 ,recently issued4 ,an entirely new edition4 ,should be in the possession of all who desire to keep abreast with the progress of this branch of science4 ,complete1 concise and convenient4 #fhb pages1 #cic illustrations4 ,price #c4jj ,,dies--,,metal ,,work ,dies3 ,their ,construction and ,use for the ,modern ,working of ,sheet ,metals4 ,by ,j4 ,v4 ,,woodworth4 ,a most useful book1 and one which should be in the hands of all engaged in the press working of metals2 treating on the ,designing1 ,constructing1 and ,use of ,tools1 ,fixtures and ,devices1 together with the manner in which they should be used in the ,power ,press1 for the cheap and rapid production of the great variety of sheet-metal articles now in use4 ,it is designed as a guide to the production of sheet-metal parts at the minimum of cost with the maximum of output4 ,the hardening and tempering of ,press tools and the classes of work which may be produced to the best advantage by the use of dies in the power press are fully treated4 ,its #eae illustrations show dies1 press fixtures and sheet-metal working devices1 the descriptions of which are so clear and practical that all metal-working mechanics will be able to understand how to design1 construct and use them4 ,many of the dies and press fixtures treated were either constructed by the author or under his supervision4 ,others were built by skilful mechanics and are in use in large sheet-metal establishments and machine shops4 #fth ,revised and ,enlarged ,edition4 ,price #c4jj ,punches1 ,dies and ,tools for ,manufacturing in ,presses4 ,by ,j4 ,v4 ,,woodworth4 ,this work is a companion volume to the author's elementary work entitled ,dies3 ,their ,construction and ,use4 ,it does not go into the details of die-making to the extent of the author's previous book1 but gives a comprehensive review of the field of operations carried on by presses4 ,a large part of the information given has been drawn from the author's personal experience4 ,it might well be termed an ,encyclopedia of ,die-,making1 ,punch-,making1 ,die-,sinking1 ,sheet-,metal ,working1 and ,making of ,special ,tools1 ,sub-presses1 ,devices and ,mechanical ,combinations for ,punching1 ,cutting1 ,bending1 ,forming1 ,piercing1 ,drawing1 ,compressing and ,assembling ,sheet-,metal ,parts1 and also ,articles of other ,materials in ,machine ,tools4 #b;d ,edition4 ,price #d4jj ,drop ,forging1 ,die-,sinking and ,machine-,forming of ,steel4 ,by ,j4 ,v4 ,,woodworth4 ,this is a practical treatise on ,modern ,shop ,practice1 ,processes1 ,methods1 ,machine ,tools1 and ,details treating on the ,hot and ,cold ,machine-,forming of ,steel and ,iron into ,finished ,shapes3 together with ,tools1 ,dies1 and ,machinery involved in the manufacture of ,duplicate ,forgings and ,interchangeable ,hot and ,cold ,pressed ,parts from ,bar and ,sheet ,metal4 ,this book fills a demand of long standing for information regarding drop-forgings1 die-sinking and machine-forming of steel and the shop practice involved1 as it actually exists in the modern drop-forging shop4 ,the processes of die-sinking and force-making1 which are thoroughly described and illustrated in this admirable work1 are rarely to be found explained in such a clear and concise manner as is here set forth4 ,the process of die-sinking relates to the engraving or sinking of the female or lower dies1 such as are used for drop-forgings1 hot and cold machine-forging1 swedging1 and the press working of metals4 ,the process of force-making relates to the engraving or raising of the male or upper dies used in producing the lower dies for the press-forming and machine-forging of duplicate parts of metal4 ,in addition to the arts above mentioned the book contains explicit information regarding the drop-forging and hardening plants1 designs1 conditions1 equipment1 drop hammers1 forging machines1 etc41 machine forging1 hydraulic forging1 autogenous welding and shop practice4 ,the book contains eleven chapters1 and the information contained in these chapters is just what will prove most valuable to the forged-metal worker4 ,all operations described in the work are thoroughly illustrated by means of perspective half-tones and outline sketches of the machinery employed4 #cjj detailed illustrations4 ,price #b4ej ,,drawing--,,sketching ,,paper ,practical ,perspective4 ,by ,,richards and ,,colvin4 ,shows just how to make all kinds of mechanical drawings in the only practical perspective isometric4 ,makes everything plain1 so that any mechanic can understand a sketch or drawing in this way4 ,saves time in the drawing room1 and mistakes in the shops4 ,contains practical examples of various classes of work4 #dth ,edition4 ,price #ej cents ,linear ,perspective ,self-,taught4 ,by ,,herman ,t4 ,c4 ,,kraus4 ,this work gives the theory and practice of linear perspective1 as used in architectural1 engineering and mechanical drawings4 ,persons taking up the study of the subject by themselves will be able1 by the use of the instruction given1 to readily grasp the subject1 and by reasonable practice become good perspective draftsmen4 ,the arrangement of the book is good2 the plate is on the left-hand1 while the descriptive text follows on the opposite page1 so as to be readily referred to4 ,the drawings are on sufficiently large scale to show the work clearly and are plainly figured4 ,there is included a self-explanatory chart which gives all information necessary for the thorough understanding of perspective4 ,this chart alone is worth many times over the price of the book4 #b;d ,revised and ,enlarged ,edition4 ,price #b4ej ,self-,taught ,mechanical ,drawing and ,elementary ,machine ,design4 ,by ,f4 ,l4 ,,sylvester1 ,m4,e41 ,draftsman1 with additions by ,,erik ,,oberg1 associate editor of ,machinery4 ,this is a practical treatise on ,mechanical ,drawing and ,machine ,design1 comprising the first principles of geometric and mechanical drawing1 workshop mathematics1 mechanics1 strength of materials and the calculations and design of machine details4 ,the author's aim has been to adapt this treatise to the requirements of the practical mechanic and young draftsman and to present the matter in as clear and concise a manner as possible4 ,to meet the demands of this class of students1 practically all the important elements of machine design have been dealt with1 and in addition algebraic formulas have been explained1 and the elements of trigonometry treated in the manner best suited to the needs of the practical man4 ,the book is divided into #bj chapters1 and in arranging the material1 mechanical drawing1 pure and simple1 has been taken up first1 as a thorough understanding of the principles of representing objects facilitates the further study of mechanical subjects4 ,this is followed by the mathematics necessary for the solution of the problems in machine design which are presented later1 and a practical introduction to theoretical mechanics and the strength of materials4 ,the various elements entering into machine design1 such as cams1 gears1 sprocket-wheels1 cone pulleys1 bolts1 screws1 couplings1 clutches1 shafting and fly-wheels1 have been treated in such a way as to make possible the use of the work as a text-book for a continuous course of study4 ,it is easily comprehended and assimilated even by students of limited previous training4 #ccj pages1 #bae engravings4 ,price #b4jj ,a ,new ,sketching ,paper4 ,a new specially ruled paper to enable you to make sketches or drawings in isometric perspective without any figuring or fussing4 ,it is being used for shop details as well as for assembly drawings1 as it makes one sketch do the work of three1 and no workman can help seeing just what is wanted4 ,pads of #dj sheets1 #fx#i inches4 ,price #be cents ,pads of #dj sheets1 #ix#ab inches4 ,price #ej cents #dj sheets1 #abx#ah inches4 ,price #a4jj ,,electricity ,arithmetic of ,electricity4 ,by ,prof4 ,t4 ,o',,conor ,,sloane4 ,a practical treatise on electrical calculations of all kinds reduced to a series of rules1 all of the simplest forms1 and involving only ordinary arithmetic2 each rule illustrated by one or more practical problems1 with detailed solution of each one4 ,this book is classed among the most useful works published on the science of electricity1 covering as it does the mathematics of electricity in a manner that will attract the attention of those who are not familiar with algebraical formulas4 #bjth ,edition4 #afj pages4 ,price #a4jj ,commutator ,construction4 ,by ,,wm4 ,,baxter1 ,,jr4 ,the business end of any dynamo or motor of the direct current type is the commutator4 ,this book goes into the designing1 building1 and maintenance of commutators1 shows how to locate troubles and how to remedy them2 everyone who fusses with dynamos needs this4 #dth ,edition4 ,price #be cents ,dynamo ,building for ,amateurs1 or ,how to ,construct a ,fifty-,watt ,dynamo4 ,by ,,arthur ,j4 ,,weed1 ,member of ,n4 ,y4 ,electrical ,society4 ,a practical treatise showing in detail the construction of a small dynamo or motor1 the entire machine work of which can be done on a small foot lathe4 ,dimensioned working drawings are given for each piece of machine work1 and each operation is clearly described4 ,this machine1 when used as a dynamo1 has an output of fifty watts2 when used as a motor it will drive a small drill press or lathe4 ,it can be used to drive a sewing machine on any and all ordinary work4 ,the book is illustrated with more than sixty original engravings1 showing the actual construction of the different parts4 ,among the contents are chapters on3 #a4 ,fifty-,watt ,dynamo4 #b4 ,side ,bearing ,rods4 #c4 ,field ,punching4 #d4 ,bearings4 #e4 ,commutator4 #f4 ,pulley4 #g4 ,brush ,holders4 #h4 ,connection ,board4 #i4 ,armature ,shaft4 #aj4 ,armature4 #aa4 ,armature ,winding4 #ab4 ,field ,winding4 #ac4 ,connecting and starting4 ,paper4 ,price #ej ,cents ,cloth4 ,price #a4jj ,electric ,bells4 ,by ,m4 ,b4 ,,sleeper4 ,a complete treatise for the practical worker in ,installing1 ,operating and ,testing ,bell ,circuits1 ,burglar ,alarms1 ,thermostats1 and other apparatus used with ,electric ,bells4 ,both the electrician and the experimenter will find in this book new material which is essential in their work4 ,tools1 bells1 batteries1 unusual circuits1 burglar alarms1 annunciator systems1 thermostats1 circuit breakers1 time alarms1 and other apparatus used in bell circuits are described from the standpoints of their application1 construction and repair4 ,the detailed instruction for building the apparatus will appeal to the experimenter particularly4 ,the practical worker will find the chapter on ,wiring1 ,calculation of ,wire ,sizes and ,magnet ,winding1 ,upkeep of ,systems1 and the ,location of ,faults1 of the greatest value in their work4 ,among the chapters are3 ,tools and ,materials for ,bell ,work2 ,how and ,why ,bell ,work2 ,batteries for ,small ,installations2 ,making ,bells and ,push ,buttons2 ,wiring ,bell ,systems2 ,construction of ,annunciators and ,signals2 ,burglary ,alarms and ,auxiliary ,apparatus2 ,more ,elaborate ,bell ,systems2 ,finding ,faults and ,remedying ,them4 #abd pages1 fully illustrated4 ,price #ej cents ,electric ,lighting and ,heating ,pocket ,book4 ,by ,,sydney ,f4 ,,walker4 ,this book puts in convenient form useful information regarding the apparatus which is likely to be attached to the mains of an electrical company4 ,tables of units and equivalents are included and useful electrical laws and formulas are stated4 #dch pages1 #cjj engravings4 ,bound in leather4 ,pocket book form4 ,price #c4jj ,electric ,wiring1 ,diagrams and ,switchboards4 ,by ,,newton ,,harrison1 with additions by ,,thomas ,,poppe4 ,a thoroughly practical treatise covering the subject of ,electric ,wiring in all its branches1 deluding explanations and diagrams which are thoroughly explicit and greatly simplify the subject4 ,practical every-day problems in wiring are presented and the method of obtaining intelligent results clearly shown4 ,only arithmetic is used4 ,ohm's law is given a simple explanation with reference to wiring for direct and alternating currents4 ,the fundamental principle of drop of potential in circuits is shown with its various applications4 ,the simple circuit is developed with the position of mains1 feeders and branches2 their treatment as a part of a wiring plan and their employment in house wiring clearly illustrated4 ,some simple facts about testing are included in connection with the wiring4 ,molding and conduit work are given careful consideration2 and switchboards are systematically treated1 built up and illustrated1 showing the purpose they serve1 for connection with the circuits1 and to shunt and compound wound machines4 ,the simple principles of switchboard construction1 the development of the switchboard1 the connections of the various instruments1 including the lightning arrester1 are also plainly set forth4 ,alternating current wiring is treated1 with explanations of the power factor1 conditions calling for various sizes of wire1 and a simple way of obtaining the sizes for single-phase1 two-phase and three-phase circuits4 ,this is the only complete work issued showing and telling you what you should know about direct and alternating current wiring4 ,it is a ready reference4 ,the work is free from advanced technicalities and mathematics1 arithmetic being used throughout4 ,it is in every respect a handy1 well-written1 instructive1 comprehensive volume on wiring for the wireman1 foreman1 contractor1 or electrician4 #bnd ,revised ,edition4 #cjc pages1 #acj illustrations4 ,price #a4ej ,electric ,furnaces and their ,industrial ,applications4 ,by ,j4 ,,wright4 ,this is a book which will prove of interest to many classes of people3 the manufacturer who desires to know what product can be manufactured successfully in the electric furnace1 the chemist who wishes to post himself on the electro-chemistry1 and the student of science who merely looks into the subject from curiosity4 ,new1 ,revised and ,enlarged ,edition4 #cbj pages4 ,fully illustrated1 cloth4 ,price #c4jj ,electric ,toy ,making1 ,dynamo ,building1 and ,electric ,motor ,construction4 ,by ,prof4 ,t4 ,o',,conor ,,sloane4 ,this work treats of the making at home of electrical toys1 electrical apparatus1 motors1 dynamos1 and instruments in general1 and is designed to bring within the reach of young and old the manufacture of genuine and useful electrical appliances4 ,the work is especially designed for amateurs and young folks4 ,thousands of our young people are daily experimenting1 and busily engaged in making electrical toys and apparatus of various kinds4 ,the present work is just what is wanted to give the much needed information in a plain1 practical manner1 with illustrations to make easy the carrying out of the work4 #bjth ,edition4 ,price #a4jj ,practical ,electricity4 ,by ,prof4 ,t4 ,o',,conor ,,sloane4 ,this work of #gfh pages was previously known as ,sloane's ,electricians' ,hand ,book1 and is intended for the practical electrician who has to make things go4 ,the entire field of electricity is covered within its pages4 ,among some of the subjects treated are3 ,the ,theory of the ,electric ,current and ,circuit1 ,electro-,chemistry1 ,primary ,batteries1 ,storage ,batteries1 ,generation and ,utilization of ,electric ,powers1 ,alternating ,current1 ,armature ,winding1 ,dynamos and ,motors1 ,motor ,generators1 ,operation of the ,central ,station ,switchboards1 ,safety ,appliances1 ,distribution of ,electric ,light and ,power1 ,street ,mains1 ,transformers1 ,arc and ,incandescent ,lighting1 ,electric ,measurements1 ,photometry1 ,electric ,railways1 ,telephony1 ,bell-,wiring1 ,electric-,plating1 ,electric ,heating1 ,wireless ,telegraphy1 etc4 ,it contains no useless theory2 everything is to the point4 ,it teaches you just what you want to know about electricity4 ,it is the standard work published on the subject4 ,forty-one chapters1 #eef engravings4 ,price #b4ej ,electricity ,simplified4 ,by ,prof4 ,t4 ,o',,conor ,,sloane4 ,the object of ,electricity ,simplified is to make the subject as plain as possible and to show what the modern conception of electricity is2 to show how two plates of different metal1 immersed in acid1 can send a message around the globe2 to explain how a bundle of copper wire rotated by a steam engine can be the agent in lighting our streets2 to tell what the volt1 ohm and ampere are1 and what high and low tension mean2 and to answer the questions that perpetually arise in the mind in this age of electricity4 #acth ,edition4 #agb pages4 ,illustrated4 ,price #a4jj ,house ,wiring4 ,by ,,thomas ,w4 ,,poppe4 ,this work describes and illustrates the actual installation of ,electric ,light ,wiring1 the manner in which the work should be done1 and the method of doing it4 ,the book can be conveniently carried in the pocket4 ,it is intended for the ,electrician1 ,helper and ,apprentice4 ,it solves all ,wiring ,problems and contains nothing that conflicts with the rulings of the ,national ,board of ,fire ,underwriters4 ,it gives just the information essential to the ,successful ,wiring of a ,building4 ,among the subjects treated are3 ,locating the ,meter4 ,panel-,boards4 ,switches4 ,plug ,receptacles4 ,brackets4 ,ceiling ,fixtures4 ,the ,meter ,connections4 ,the ,feed ,wires4 ,the ,steel ,armored ,cable ,system4 ,the ,flexible ,steel ,conduit ,system4 ,the ,ridig ,conduit ,system4 ,a digest of the ,national ,board of ,fire ,underwriters' rules relating to metallic wiring systems4 ,various switching arrangements explained and diagrammed4 ,the easiest method of testing the ,three- and ,four-way circuits explained4 ,the grounding of all metallic wiring systems and the reason for doing so shown and explained4 ,the insulation of the metal parts of lamp fixtures and the reason for the same described and illustrated4 #abe pages4 #bnd ,edition1 revised and enlarged4 ,fully illustrated4 ,flexible cloth4 ,price #ej cents ,how to ,become a ,successful ,electrician4 ,by ,prof4 ,t4 ,o',,conor ,,sloane4 ,every young man who wishes to become a successful electrician should read this book4 ,it tells in simple language the surest and easiest way to become a successful electrician4 ,the studies to be followed1 methods of work1 field of operation and the requirements of the successful electrician are pointed out and fully explained4 ,every young engineer will find this an excellent stepping stone to more advanced works on electricity which he must master before success can be attained4 ,many young men become discouraged at the very outstart by attempting to read and study books that are far beyond their comprehension4 ,this book serves as the connecting link between the rudiments taught in the public schools and the real study of electricity4 ,it is interesting from cover to cover4 #ahth ,revised ,edition1 just issued4 #bje pages4 ,illustrated4 ,price #a4jj ,management of ,dynamos4 ,by ,,lummis-,,paterson4 ,a handbook of theory and practice4 ,this work is arranged in three parts4 ,the first part covers the elementary theory of the dynamo4 ,the second part1 the construction and action of the different classes of dynamos in common use are described2 while the third part relates to such matters as affect the practical management and working of dynamos and motors4 #dth ,edition4 #bib pages1 #aag illustrations4 ,price #a4ej ,standard ,electrical ,dictionary4 ,by ,t4 ,o',,conor ,,sloane4 ,an indispensable work to all interested in electrical science4 ,suitable alike for the student and professional4 ,a practical handbook of reference containing definitions of about #e1jjj distinct words1 terms and phrases4 ,the definitions are terse and concise and include every term used in electrical science4 ,recently issued4 ,an entirely new edition4 ,should be in the possession of all who desire to keep abreast with the progress of this branch of science4 ,in its arrangement and typography the book is very convenient4 ,the word or term defined is printed in black-faced type1 which readily catches the eye1 while the body of the page is in smaller but distinct type4 ,the definitions are well worded1 and so as to be understood by the non-technical reader4 ,the general plan seems to be to give an exact1 concise definition1 and then amplify and explain in a more popular way4 ,synonyms are also given1 and references to other words and phrases are made4 ,a very complete and accurate index of fifty pages is at the end of the volume2 and as this index contains all synonyms1 and as all phrases are indexed in every reasonable combination of words1 reference to the proper place in the body of the book is readily made4 ,it is difficult to decide how far a book of this character is to keep the dictionary form1 and to what extent it may assume the encyclopedia form4 ,for some purposes1 concise1 exactly worded definitions are needed2 for other purposes1 more extended descriptions are required4 ,this book seeks to satisfy both demands1 and does it with considerable success4 #fhb pages1 #cic illustrations4 #abth ,edition4 ,price #c4jj ,storage ,batteries ,simplified4 ,by ,,victor ,w4 ,,page1 ,m4,e4 ,a complete treatise on storage battery operating principles1 repairs and applications4 ,the greatly increasing application of storage batteries in modern engineering and mechanical work has created a demand for a book that will consider this subject completely and exclusively4 ,this is the most thorough and authoritative treatise ever published on this subject4 ,it is written in easily understandable1 non-technical language so that any one may grasp the basic principles of storage battery action as well as their practical industrial applications4 ,all electric and gasoline automobiles use storage batteries4 ,every automobile repairman1 dealer or salesman should have a good knowledge of maintenance and repair of these important elements of the motor car mechanism4 ,this book not only tells how to charge1 care for and rebuild storage batteries but also outlines all the industrial uses4 ,learn how they run street cars1 locomotives and factory trucks4 ,get an understanding of the important functions they perform in submarine boats1 isolated lighting plants1 railway switch and signal systems1 marine applications1 etc4 ,this book tells how they are used in central station standby service1 for starting automobile motors and in ignition systems4 ,every practical use of the modern storage battery is outlined in this treatise4 #cbj pages1 fully illustrated4 ,price #a4ej ,switchboards4 ,by ,,william ,,baxter1 ,,jr4 ,this book appeals to every engineer and electrician who wants to know the practical side of things4 ,it takes up all sorts and conditions of dynamos1 connections and circuits1 and shows by diagram and illustration just how the switchboard should be connected4 ,includes direct and alternating current boards1 also those for arc lighting1 incandescent and power circuits4 ,special treatment on high voltage boards for power transmission4 #bnd ,edition4 #aij pages1 ,illustrated4 ,price #a4ej ,telephone ,construction1 ,installation1 ,wiring1 ,operation and ,maintenance4 ,by ,w4 ,h4 ,,radcliffe and ,h4 ,c4 ,,cushing4 ,this book is intended for the amateur1 the wireman1 or the engineer who desires to establish a means of telephonic communication between the rooms of his home1 office1 or shop4 ,it deals only with such things as may be of use to him rather than with theories4 ,gives the principles of construction and operation of both the ,bell and ,independent instruments2 approved methods of installing and wiring them2 the means of protecting them from lightning and abnormal currents2 their connection together for operation as series or bridging stations2 and rules for their inspection and maintenance4 ,line wiring and the wiring and operation of special telephone systems are also treated4 ,intricate mathematics are avoided1 and all apparatus1 circuits and systems are thoroughly described4 ,the appendix contains definitions of units and terms used in the text4 ,selected wiring tables1 which are very helpful1 are also included4 ,among the subjects treated are ,construction1 ,operation1 and ,installation of ,telephone ,instruments2 ,inspection and ,maintenance of ,telephone ,instruments2 ,telephone ,line ,wiring2 ,testing ,telephone ,line ,wires and ,cables2 ,wiring and ,operation of ,special ,telephone ,systems1 etc4 #bnd ,edition1 ,revised and ,enlarged4 #bbc pages1 #aed illustrations4 ,price #a4jj ,wireless ,telegraphy and ,telephony ,simply ,explained4 ,by ,,alfred ,p4 ,,morgan4 ,this is undoubtedly one of the most complete and comprehensible treatises on the subject ever published1 and a close study of its pages will enable one to master all the details of the wireless transmission of messages4 ,the author has filled a long-felt want and has succeeded in furnishing a lucid1 comprehensible explanation in simple language of the theory and practice of wireless telegraphy and telephony4 ,among the contents are3 ,introductory2 ,wireless ,transmission and ,reception--,the ,aerial ,system1 ,earth ,connections--,the ,transmitting ,apparatus1 ,spark ,coils and ,transformers1 ,condensers1 ,helixes1 ,spark ,gaps1 ,anchor ,gaps1 ,aerial ,switches--,the ,receiving ,apparatus1 ,detectors1 etc4--,tuning and ,coupling1 ,tuning ,coils1 ,loose ,couplers1 ,variable ,condensers1 ,directive ,wave ,systems--,miscellaneous ,apparatus1 ,telephone ,receivers1 ,range of ,stations1 ,static ,interference--,wireless ,telephones1 ,sound and ,sound ,waves1 ,the ,vocal ,cords and ,ear--,wireless ,telephone1 ,how ,sounds ,are ,changed into ,electric ,waves--,wireless ,telephones1 ,the ,apparatus--,summary4 #aed pages1 #aef engravings4 ,price #a4jj ,wiring a ,house4 ,by ,,herbert ,,pratt4 ,shows a house already built2 tells just how to start about wiring it2 where to begin2 what wire to use2 how to run it according to ,insurance ,rules2 in fact1 just the information you need4 ,directions apply equally to a shop4 #dth ,edition4 ,price #be cents ,,factory ,,management1 ,,etc4 ,modern ,machine ,shop ,construction1 ,equipment and ,management4 ,by ,o4 ,e4 ,,perrigo1 ,m4,e4 ,the only work published that describes the modern machine shop or manufacturing plant from the time the grass is growing on the site intended for it until the finished product is shipped4 ,by a careful study of its thirty-two chapters the practical man may economically build1 efficiently equip1 and successfully manage the modern machine shop or manufacturing establishment4 ,just the book needed by those contemplating the erection of modern shop buildings1 the rebuilding and reorganization of old ones1 or the introduction of modern shop methods1 time and cost systems4 ,it is a book written and illustrated by a practical shop man for practical shop men who are too busy to read theories and want facts4 ,it is the most complete all-around book of its kind ever published4 ,it is a practical book for practical men1 from the apprentice in the shop to the president in the office4 ,it minutely describes and illustrates the most simple and yet the most efficient time and cost system yet devised4 #bnd ,revised and ,enlarged ,edition1 just issued4 #chd pages1 #bai illustrations4 ,price #e4jj ,,fuel ,combustion of ,coal and the ,prevention of ,smoke4 ,by ,,wm4 ,m4 ,,barr4 ,this book has been prepared with special reference to the generation of heat by the combustion of the common fuels found in the ,united ,states1 and deals particularly with the conditions necessary to the economic and smokeless combustion of bituminous coals in ,stationary and ,locomotive ,steam ,boilers4 ,the presentation of this important subject is systematic and progressive4 ,the arrangement of the book is in a series of practical questions to which are appended accurate answers1 which describe in language1 free from technicalities1 the several processes involved in the furnace combustion of ,american fuels2 it clearly states the essential requisites for perfect combustion1 and points out the best methods for furnace construction for obtaining the greatest quantity of heat from any given quality of coal4 ,nearly #cej pages1 fully illustrated4 ,price #a4jj ,smoke ,prevention and ,fuel ,economy4 ,by ,,booth and ,,kershaw4 ,a complete treatise for all interested in smoke prevention and combustion1 being based on the ,german work of ,ernst ,schmatolla1 but it is more than a mere translation of the ,german treatise1 much being added4 ,the authors show as briefly as possible the principles of fuel combustion1 the methods which have been and are at present in use1 as well as the proper scientific methods for obtaining all the energy in the coal and burning it without smoke4 ,considerable space is also given to the examination of the waste gases1 and several of the representative ,english and ,american mechanical stoker and similar appliances are described4 ,the losses carried away in the waste gases are thoroughly analyzed and discussed in the ,appendix1 and abstracts are also here given of various patents on combustion apparatus4 ,the book is complete and contains much of value to all who have charge of large plants4 #aid pages4 ,illustrated4 ,price #b4ej ,,gas ,,engines ,,and ,,gas ,gas1 ,gasoline and ,oil ,engines4 ,by ,,gardner ,d4 ,,hiscox4 ,revised by ,,victor ,w4 ,,page1 ,m4,e4 ,just issued ,new #aiah ,edition1 ,revised and ,enlarged4 ,every user of a gas engine needs this book4 ,simple1 instructive and right up-to-date4 ,the only complete work on the subject4 ,tells all about internal combustion engineering1 treating exhaustively on the design1 construction and practical application of all forms of gas1 gasoline1 kerosene and crude petroleum-oil engines4 ,describes minutely all auxiliary systems1 such as lubrication1 carburetion and ignition4 ,considers the theory and management of all forms of explosive motors for stationary and marine work1 automobiles1 aeroplanes and motor-cycles4 ,includes also ,producer ,gas and ,its ,production4 ,invaluable instructions for all students1 gas-engine owners1 gas-engineers1 patent experts1 designers1 mechanics1 draftsmen and all having to do with the modern power4 ,illustrated by over #djj engravings1 many specially made from engineering drawings1 all in correct proportion4 #fej pages1 #dce engravings4 ,price #b4ej net ,the ,gasoline ,engine on the ,farm3 ,its ,operation1 ,repair and ,uses4 ,by ,,xeno ,w4 ,,putnam4 ,this is a practical treatise on the ,gasoline and ,kerosene ,engine intended for the man who wants to know just how to manage his engine and how to apply it to all kinds of farm work to the best advantage4 ,this book abounds with hints and helps for the farm and suggestions for the home and house-wife4 ,there is so much of value in this book that it is impossible to adequately describe it in such small space4 ,suffice to say that it is the kind of a book every farmer will appreciate and every farm home ought to have4 ,includes selecting the most suitable engine for farm work1 its most convenient and efficient installation1 with chapters on troubles1 their remedies1 and how to avoid them4 ,the care and management of the farm tractor in plowing1 harrowing1 harvesting and road grading are fully covered2 also plain directions are given for handling the tractor on the road4 ,special attention is given to relieving farm life of its drudgery by applying power to the disagreeable small tasks which must otherwise be done by hand4 ,many home made contrivances for cutting wood1 supplying kitchen1 garden1 and barn with water1 loading1 hauling and unloading hay1 delivering grain to the bins or the feed trough are included2 also full directions for making the engine milk the cows1 churn1 wash1 sweep the house and clean the windows1 etc4 ,very fully illustrated with drawings of working parts and cuts showing ,stationary1 ,portable and ,tractor ,engines doing all kinds of farm work4 ,all money-making farms utilize power4 ,learn how to utilize power by reading the pages of this book4 ,it is an aid to the result getter1 invaluable to the up-to-date farmer1 student1 blacksmith1 implement dealer and1 in fact1 all who can apply practical knowledge of stationary gasoline engines or gas tractors to advantage4 #ecj pages4 ,nearly #ahj engravings4 ,price #b4jj ,,what ,,is ,,said ,,of ,,this ,,book3 ,am much pleased with the book and find it to be very complete and up-to-date4 ,i will heartily recommend it to students and farmers whom ,i think would stand in need of such a work1 as ,i think it is an exceptionally good one4--,n4 ,s4 ,gardiner1 ,prof4 in ,charge1 ,clemson ,agr4 ,college of ,s4 ,c42 ,dept4 of ,agri4 and ,agri4 ,exp4 ,station1 ,clemson ,college1 ,s4 ,c4 ,i feel that ,mr4 ,putnam's book covers the main points which a farmer should know4--,r4 ,t4 ,burdick1 ,instructor in ,agronomy1 ,university of ,vermont1 ,burlington1 ,vt4 ,gasoline ,engines3 ,their ,operation1 ,use and ,care4 ,by ,a4 ,,hyatt ,,verrill4 ,the simplest1 latest and most comprehensive popular work published on ,gasoline ,engines1 describing what the ,gasoline ,engine is2 its construction and operation2 how to install it2 how to select it2 how to use it and how to remedy troubles encountered4 ,intended for ,owners1 ,operators and ,users of ,gasoline ,motors of all kinds4 ,this work fully describes and illustrates the various types of ,gasoline ,engines used in ,motor ,boats1 ,motor ,vehicles and ,stationary ,work4 ,the parts1 accessories and appliances are described with chapters on ignition1 fuel1 lubrication1 operation and engine troubles4 ,special attention is given to the care1 operation and repair of motors1 with useful hints and suggestions on emergency repairs and makeshifts4 ,a complete glossary of technical terms and an alphabetically arranged table of troubles and their symptoms form most valuable and unique features of this manual4 ,nearly every illustration in the book is original1 having been made by the author4 ,every page is full of interest and value4 ,a book which you cannot afford to be without4 #bge pages1 #aeb specially made engravings4 ,price #a4ej ,gas ,engine ,construction1 or ,how to ,build a ,half-horsepower ,gas ,engine4 ,by ,,parsell and ,,weed4 ,a practical treatise of #cjj pages describing the theory and principles of the action of ,gas ,engines of various types and the design and construction of a half-horsepower ,gas ,engine1 with illustrations of the work in actual progress1 together with the dimensioned working drawings1 giving clearly the sizes of the various details2 for the student1 the scientific investigator1 and the amateur mechanic4 ,this book treats of the subject more from the standpoint of practice than that of theory4 ,the principles of operation of ,gas ,engines are clearly and simply described1 and then the actual construction of a half-horsepower engine is taken up1 step by step1 showing in detail the making of the ,gas ,engine4 #crd ,edition4 #cjj pages4 ,price #b4ej ,how to ,run and ,install ,two- and ,four-,cycle ,marine ,gasoline ,engines4 ,by ,c4 ,,von ,,culin4 ,revised and enlarged edition just issued4 ,the object of this little book is to furnish a pocket instructor for the beginner1 the busy man who uses an engine for pleasure or profit1 but who does not have the time or inclination for a technical book1 but simply to thoroughly understand how to properly operate1 install and care for his own engine4 ,the index refers to each trouble1 remedy1 and subject alphabetically4 ,being a quick reference to find the cause1 remedy and prevention for troubles1 and to become an expert with his own engine4 ,pocket size4 ,paper binding4 ,price #be cents ,modern ,gas ,engines and ,producer ,gas ,plants4 ,by ,r4 ,e4 ,,mathot4 ,a guide for the gas engine designer1 user1 and engineer in the construction1 selection1 purchase1 installation1 operation1 and maintenance of gas engines4 ,more than one book on gas engines has been written1 but not one has thus far even encroached on the field covered by this book4 ,above all1 ,mr4 ,mathot's work is a practical guide4 ,recognizing the need of a volume that would assist the gas engine user in understanding thoroughly the motor upon which he depends for power1 the author has discussed his subject without the help of any mathematics and without elaborate theoretical explanations4 ,every part of the gas engine is described in detail1 tersely1 clearly1 with a thorough understanding of the requirements of the mechanic4 ,helpful suggestions as to the purchase of an engine1 its installation1 care1 and operation1 form a most valuable feature of the work4 #cbj pages1 #age detailed illustrations4 ,price #b4ej ,the ,modern ,gas ,tractor4 ,by ,,victor ,w4 ,,page1 ,m4 ,e4 ,a complete treatise describing all types and sizes of gasoline1 kerosene and oil tractors4 ,considers design and construction exhaustively1 gives complete instructions for care1 operation and repair1 outlines all practical applications on the road and in the field4 ,the best and latest work on farm tractors and tractor power plants4 ,a work needed by farmers1 students1 blacksmiths1 mechanics1 salesmen1 implement dealers1 designers and engineers4 #bnd ,edition1 ,revised4 #ejd pages1 #bbh illustrations1 #c folding plates4 ,price #b4jj ,,gearing ,,and ,,cams ,bevel ,gear ,tables4 ,by ,d4 ,,ag4 ,,engstrom4 ,a book that will at once commend itself to mechanics and draftsmen4 ,does away with all the trigonometry and fancy figuring on bevel gears1 and makes it easy for anyone to lay them out or make them just right4 ,there are #cf full-page tables that show every necessary dimension for all sizes or combinations you're apt to need4 ,no puzzling1 figuring or guessing4 ,gives placing distance1 all the angles 7including cutting angles71 and the correct cutter to use4 ,a copy of this prepares you for anything in the bevel-gear line4 #crd ,edition4 #ff pages4 ,price #a4jj ,change ,gear ,devices4 ,by ,,oscar ,e4 ,,perrigo4 ,a practical book for every designer1 draftsman1 and mechanic interested in the invention and development of the devices for feed changes on the different machines requiring such mechanism4 ,all the necessary information on this subject is taken up1 analyzed1 classified1 sifted1 and concentrated for the use of busy men who have not the time to go through the masses of irrelevant matter with which such a subject is usually encumbered and select such information as will be useful to them4 ,it shows just what has been done1 how it has been done1 when it was done1 and who did it4 ,it saves time in hunting up patent records and re-inventing old ideas4 #hh pages4 #crd ,edition4 ,price #a4jj ,drafting of ,cams4 ,by ,,louis ,,rouillion4 ,the laying out of cams is a serious problem unless you know how to go at it right4 ,this puts you on the right road for practically any kind of cam you are likely to run up against4 #crd ,edition4 ,price #be ,cents ,,hydraulics ,hydraulic ,engineering4 ,by ,,gardner ,d4 ,,hiscox4 ,a treatise on the properties1 power1 and resources of water for all purposes4 ,including the measurement of streams1 the flow of water in pipes or conduits2 the horsepower of falling water1 turbine and impact water-wheels1 wave motors1 centrifugal1 reciprocating and air-lift pumps4 ,with #cjj figures and diagrams and #cf practical tables4 ,all who are interested in water-works development will find this book a useful one1 because it is an entirely practical treatise upon a subject of present importance and cannot fail in having a far-reaching influence1 and for this reason should have a place in the working library of every engineer4 ,among the subjects treated are3 ,historical ,hydraulics2 ,properties of ,water2 ,measurement of the ,flow of ,streams2 ,flow from ,sub-surface ,orifices and ,nozzles2 ,flow of ,water in ,pipes2 ,siphons of ,various ,kinds2 ,dams and ,great ,storage ,reservoirs2 ,city and ,town ,water ,supply2 ,wells and ,their ,reinforcement2 ,air-lift ,methods of ,raising ,water2 ,artesian ,wells2 ,irrigation of ,arid ,districts2 ,water ,power2 ,water ,wheels2 ,pumps and ,pumping ,machinery2 ,reciprocating ,pumps2 ,hydraulic ,power ,transmission2 ,hydraulic ,mining2 ,canals2 ,ditches2 ,conduits and ,pipe ,lines2 ,marine ,hydraulics2 ,tidal and ,sea ,wave ,power1 etc4 #cbj pages4 ,price #d4jj ,,ice ,,and ,,refrigeration ,pocketbook of ,refrigeration and ,ice ,making4 ,by ,a4 ,j4 ,,wallis-,,taylor4 ,this is one of the latest and most comprehensive reference books published on the subject of refrigeration and cold storage4 ,it explains the properties and refrigerating effect of the different fluids in use1 the management of refrigerating machinery and the construction and insulation of cold rooms with their required pipe surface for different degrees of cold2 freezing mixtures and non-freezing brines1 temperatures of cold rooms for all kinds of provisions1 cold storage charges for all classes of goods1 ice making and storage of ice1 data and memoranda for constant reference by refrigerating engineers1 with nearly one hundred tables containing valuable references to every fact and condition required in the installment and operation of a refrigerating plant4 ,new edition just published4 ,price #a4ej ,,inventions--,,patents ,inventors' ,manual3 ,how to ,make a ,patent ,pay4 ,this is a book designed as a guide to inventors in perfecting their inventions1 taking out their patents and disposing of them4 ,it is not in any sense a ,patent ,solicitor's ,circular nor a ,patent ,broker's ,advertisement4 ,no advertisements of any description appear in the work4 ,it is a book containing a quarter of a century's experience of a successful inventor1 together with notes based upon the experience of many other inventors4 ,among the subjects treated in this work are3 ,how to ,invent4 ,how to ,secure a ,good ,patent4 ,value of ,good ,invention4 ,how to ,exhibit an ,invention4 ,how to ,interest ,capital4 ,how to ,estimate the ,value of a ,patent4 ,value of ,design ,patents4 ,value of ,foreign ,patents4 ,value of ,small ,inventions4 ,advice on ,selling ,patents4 ,advice on the ,formation of ,stock ,companies4 ,advice on the ,formation of ,limited ,liability ,companies4 ,advice on ,disposing of ,old ,patents4 ,advice as to ,patent ,attorneys4 ,advice as to ,selling ,agents4 ,forms of ,assignments4 ,license and ,contracts4 ,state ,laws ,concerning ,patent ,rights4 #aijj ,census of the ,united ,states by ,counts of ,over #aj1jjj ,population4 ,revised ,edition4 #abj pages4 ,price #a4jj ,,knots ,knots1 ,splices and ,rope ,work4 ,by ,a4 ,,hyatt ,,verrill4 ,this is a practical book giving complete and simple directions for making all the most useful and ornamental knots in common use1 with chapters on ,splicing1 ,pointing1 ,seizing1 ,serving1 etc4 ,this book is fully illustrated with #aed original engravings1 which show how each knot1 tie or splice is formed1 and its appearance when finished4 ,the book will be found of the greatest value to ,campers1 ,yachtsmen1 ,travelers1 ,boy ,scouts1 in fact1 to anyone having occasion to use or handle rope or knots for any purpose4 ,the book is thoroughly reliable and practical1 and is not only a guide1 but a teacher4 ,it is the standard work on the subject4 ,among the contents are3 #a4 ,cordage1 ,kinds of ,rope4 ,construction of ,rope1 ,parts of ,rope ,cable and ,bolt ,rope4 ,strength of ,rope1 ,weight of ,rope4 #b4 ,simple ,knots and ,bends4 ,terms ,used in ,handling ,rope4 ,seizing ,rope4 #c4 ,ties and ,hitches4 #d4 ,noose1 ,loops and ,mooring ,knots4 #e4 ,shortenings1 ,grommets and ,salvages4 #f4 ,lashings1 ,seizings and ,splices4 #g4 ,fancy ,knots and ,rope ,work4 #abh pages1 #aej original engravings4 #bnd ,revised ,edition4 ,price #ge cents ,,lathe ,,work ,lathe ,design1 ,construction1 and ,operation1 with ,practical ,examples of ,lathe ,work4 ,by ,,oscar ,e4 ,,perrigo4 ,a new1 revised edition1 and the only complete ,american work on the subject1 written by a man who knows not only how work ought to be done1 but who also knows how to do it1 and how to convey this knowledge to others4 ,it is strictly up-to-date in its descriptions and illustrations4 ,lathe history and the relations of the lathe to manufacturing are given2 also a description of the various devices for feeds and thread-cutting mechanisms from early efforts in this direction to the present time4 ,lathe design is thoroughly discussed1 including back gearing1 driving cones1 thread-cutting gears1 and all the essential elements of the modern lathe4 ,the classification of lathes is taken up1 giving the essential differences of the several types of lathes including1 as is usually understood1 engine lathes1 bench lathes1 speed lathes1 forge lathes1 gap lathes1 pulley lathes1 forming lathes1 multiple-spindle lathes1 rapid-reduction lathes1 precision lathes1 turret lathes1 special lathes1 electrically driven lathes1 etc4 ,in addition to the complete exposition on construction and design1 much practical matter on lathe installation1 care and operation has been incorporated in the enlarged new edition4 ,all kinds of lathe attachments for drilling1 milling1 etc41 are described and complete instructions are given to enable the novice machinist to grasp the art of lathe operation as well as the principles involved in design4 ,a number of difficult machining operations are described at length and illustrated4 ,the new edition has nearly #ejj pages and #cej illustrations4 ,price #b4ej ,,what ,,is ,,said ,,of ,,this ,,book3 ,this is a lathe book from beginning to end1 and is just the kind of a book which one delights to consult--a masterly treatment of the subject in hand4--,engineering ,news4 ,this work will be of exceptional interest to any one who is interested in lathe practice1 as one very seldom sees such a complete treatise on a subject as this is on the lathe4--,canadian ,machinery4 ,practical ,metal ,turning4 ,by ,,joseph ,g4 ,,horner4 ,a work of #djd pages1 fully illustrated1 covering in a comprehensive manner the modern practice of machining metal parts in the lathe1 including the regular engine lathe1 its essential design1 its uses1 its tools1 its attachments1 and the manner of holding the work and performing the operations4 ,the modernized engine lathe1 its methods1 tools and great range of accurate work4 ,the turret lathe1 its tools1 accessories and methods of performing its functions4 ,chapters on special work1 grinding1 tool holders1 speeds1 feeds1 modern tool steels1 etc4 ,second edition #c4ej ,turning and ,boring ,tapers4 ,by ,,fred ,h4 ,,colvin4 ,there are two ways to turn tapers2 the right way and one other4 ,this treatise has to do with the right way2 it tells you how to start the work properly1 how to set the lathe1 what tools to use and how to use them1 and forty and one other little things that you should know4 ,fourth edition #be cents ,,liquid ,,air ,liquid ,air and the ,liquefaction of ,gases4 ,by ,t4 ,o',,conor ,,sloane4 ,this book gives the history of the theory1 discovery and manufacture of ,liquid ,air1 and contains an illustrated description of all the experiments that have excited the wonder of audiences all over the country4 ,it shows how liquid air1 like water1 is carried hundreds of miles and is handled in open buckets4 ,it tells what may be expected from it in the near future4 ,a book that renders simple one of the most perplexing chemical problems of the century4 ,startling developments illustrated by actual experiments4 ,it is not only a work of scientific interest and authority1 but is intended for the general reader1 being written in a popular style--easily understood by every one4 ,second edition4 #cfe pages4 ,price #b4jj ,,locomotive ,,engineering ,air-,brake ,catechism4 ,by ,,robert ,h4 ,,blackall4 ,this book is a standard text-book4 ,it covers the ,westinghouse ,air-,brake ,equipment1 including the ,no4 #e and the ,no4 #f ,e4-,t4 ,locomotive ,brake ,equipment2 the ,k 7,quick ,service7 ,triple ,valve for ,freight ,service2 and the ,cross-,compound ,pump4 ,the operation of all parts of the apparatus is explained in detail1 and a practical way of finding their peculiarities and defects1 with a proper remedy1 is given4 ,it contains #b1jjj questions with their answers1 which will enable any railroad man to pass any examination on the subject of ,air ,brakes4 ,endorsed and used by air-brake instructors and examiners on nearly every railroad in the ,united ,states4 ,twenty-sixth edition4 #daa pages1 fully illustrated with colored plates and diagrams4 ,price #b4jj ,american ,compound ,locomotives4 ,by ,,fred ,h4 ,,colvin4 ,the only book on compounds for the engineman or shopman that shows in a plain1 practical way the various features of compound locomotives in use4 ,shows how they are made1 what to do when they break down or balk4 ,contains sections as follows3 ,a ,bit of ,history4 ,theory of ,compounding ,steam ,cylinders4 ,baldwin ,two-,cylinder ,compound4 ,pittsburg ,two-,cylinder ,compound4 ,rhode ,island ,compound4 ,richmond ,compound4 ,rogers ,compound4 ,schenectady ,two-,cylinder ,compound4 ,vauclain ,compound4 ,tandem ,compounds4 ,baldwin ,tandem4 ,the ,colvin-,wightman ,tandem4 ,schenectady ,tandem4 ,balanced ,locomotives4 ,baldwin ,balanced ,compound4 ,plans for ,balancing4 ,locating ,blows4 ,breakdowns4 ,reducing ,valves4 ,drifting4 ,valve ,motion4 ,disconnecting4 ,power of ,compound ,locomotives4 ,practical ,notes4 ,fully illustrated and containing ten special ,duotone inserts on heavy ,plate ,paper1 showing different types of ,compounds4 #adb pages4 ,price #a4jj ,application of ,highly ,superheated ,steam to ,locomotives4 ,by ,,robert ,,garbe4 ,a practical book which cannot be recommended too highly to those motive-power men who are anxious to maintain the highest efficiency in their locomotives4 ,contains special chapters on ,generation of ,highly ,superheated ,steam2 ,superheated ,steam and the ,two-,cylinder ,simple ,engine2 ,compounding and ,superheating2 ,designs of ,locomotive ,superheaters2 ,constructive ,details of ,locomotives ,using ,highly ,superheated ,steam4 ,experimental and ,working ,results4 ,illustrated with folding plates and tables4 ,cloth4 ,price #b4ej ,combustion of ,coal and the ,prevention of ,smoke4 ,by ,,wm4 ,m4 ,,barr4 ,this book has been prepared with special reference to the generation of heat by the combustion of the common fuels found in the ,united ,states and deals particularly with the conditions necessary to the economic and smokeless combustion of bituminous coal in ,stationary and ,locomotive ,steam ,boilers4 ,presentation of this important subject is systematic and progressive4 ,the arrangement of the book is in a series of practical questions to which are appended accurate answers1 which describe in language free from technicalities the several processes involved in the furnace combustion of ,american fuels2 it clearly states the essential requisites for perfect combustion1 and points out the best methods of furnace construction for obtaining the greatest quantity of heat from any given quality of coal4 ,nearly #cej pages1 fully illustrated4 ,price #a4jj ,diary of a ,round-,house ,foreman4 ,by ,t4 ,s4 ,,reilly4 ,this is the greatest book of railroad experiences ever published4 ,containing a fund of information and suggestions along the line of handling men1 organizing1 etc41 that one cannot afford to miss4 #agf pages4 ,price #a4jj ,link ,motions1 ,valves and ,valve ,setting4 ,by ,,fred ,h4 ,,colvin1 ,associate ,editor of ,american ,machinist4 ,a handy book for the engineer or machinist that clears up the mysteries of valve setting4 ,shows the different valve gears in use1 how they work1 and why4 ,piston and slide valves of different types are illustrated and explained4 ,a book that every railroad man in the motive-power department ought to have4 ,contains chapters on ,locomotive ,link ,motion1 ,valve ,movements1 ,setting ,slide ,valves1 ,analysis by ,diagrams1 ,modern ,practice1 ,slip of ,block1 ,slice ,valves1 ,piston ,valves1 ,setting ,piston ,valves1 ,joy-,allen ,valve ,gear1 ,walschaert ,valve ,gear1 ,gooch ,valve ,gear1 ,alfree-,hubbell ,valve ,gear1 etc41 etc4 ,fully illustrated4 ,price #ej cents ,locomotive ,boiler ,construction4 ,by ,,frank ,a4 ,,kleinhans4 ,the construction of boilers in general is treated and1 following this1 the locomotive boiler is taken up in the order in which its various parts go through the shop4 ,shows all types of boilers used2 gives details of construction2 practical facts1 such as life of riveting1 punches and dies2 work done per day1 allowance for bending and flanging sheets and other data4 ,including the recent ,locomotive ,boiler ,inspection ,laws and ,examination ,questions with their answers for ,government ,inspectors4 ,contains chapters on ,laying-,out ,work2 ,flanging and ,forging2 ,punching2 ,shearing2 ,plate ,planing2 ,general ,tables2 ,finishing ,parts2 ,bending2 ,machinery ,parts2 ,riveting2 ,boiler ,details2 ,smoke-,box ,details2 ,assembling and ,calking2 ,boiler-,shop ,machinery1 etc41 etc4 ,there isn't a man who has anything to do with boiler work1 either new or repair work1 who doesn't need this book4 ,the manufacturer1 superintendent1 foreman and boiler worker--all need it4 ,no matter what the type of boiler1 you'll find a mint of information that you wouldn't be without4 ,over #djj pages1 five large folding plates4 ,price #c4jj ,locomotive ,breakdowns and their ,remedies4 ,by ,,geo4 ,l4 ,,fowler4 ,revised by ,,wm4 ,w4 ,,wood1 ,air-,brake ,instructor4 ,just issued4 ,revised pocket edition4 ,it is out of the question to try and tell you about every subject that is covered in this pocket edition of ,locomotive ,breakdowns4 ,just imagine all the common troubles that an engineer may expect to happen some time1 and then add all of the unexpected ones1 troubles that could occur1 but that you have never thought about1 and you will find that they are all treated with the very best methods of repair4 ,walschaert ,locomotive ,valve ,gear ,troubles1 ,electric ,headlight ,troubles1 as well as ,questions and ,answers on the ,air ,brake are all included4 #cab pages4 #hth ,revised ,edition4 ,fully illustrated4 ,price #a4jj ,locomotive ,catechism4 ,by ,,robert ,,grimshaw4 ,the revised edition of ,locomotive ,catechism1 by ,robert ,grimshaw1 is a ,new ,book from ,cover to ,cover4 ,it contains twice as many pages and double the number of illustrations of previous editions4 ,includes the greatest amount of practical information ever published on the construction and management of modern locomotives4 ,specially ,prepared ,chapters on the ,walschaert ,locomotive ,valve ,gear1 the ,air-,brake ,equipment and the ,electric ,headlight are given4 ,it commends itself at once to every ,engineer and ,fireman1 and to all who are going in for examination or promotion4 ,in plain language1 with full1 complete answers1 not only all the questions asked by the examining engineer are given1 but those which the young and less experienced would ask the veteran1 and which old hands ask as stickers4 ,it is a veritable ,encyclopedia of the ,locomotive1 is entirely free from mathematics1 easily understood and thoroughly up to date4 ,contains over #d1jjj ,examination ,questions with their ,answers4 #hbe pages1 #dcg illustrations1 and #c folding plates4 #bhth ,revised ,edition4 ,price #b4ej ,practical ,instructor and ,reference ,book for ,locomotive ,firemen and ,engineers4 ,by ,,chas4 ,f4 ,,lockhart4 ,an entirely new book on the ,locomotive4 ,it appeals to every railroad man1 as it tells him how things are done and the right way to do them4 ,written by a man who has had years of practical experience in locomotive shops and on the road firing and running4 ,the information given in this book cannot be found in any other similar treatise4 ,eight hundred and fifty-one questions with their answers are included1 which will prove specially helpful to those preparing for examination4 ,practical information on3 ,the ,construction and ,operation of ,locomotives1 ,breakdowns and their ,remedies1 ,air ,brakes and ,valve ,gears4 ,rules and ,signals are handled in a thorough manner4 ,as a book of reference it cannot be excelled4 ,the book is divided into six parts1 as follows3 #a4 ,the ,fireman's ,duties4 #b4 ,general ,description of the ,locomotive4 #c4 ,breakdowns and their ,remedies4 #d4 ,air ,brakes4 #e4 ,extracts from ,standard ,rules4 #f4 ,questions for ,examination4 ,the #hea questions have been carefully selected and arranged4 ,these cover the examinations required by the different railroads4 #cfh pages1 #hh illustrations4 ,price #a4ej ,prevention of ,railroad ,accidents1 or ,safety in ,railroading4 ,by ,,george ,,bradshaw4 ,this book is a heart-to-heart talk with ,railroad ,employees1 dealing with facts1 not theories1 and showing the men in the ranks1 from every-day experience1 how accidents occur and how they may be avoided4 ,the book is illustrated with seventy original photographs and drawings showing the safe and unsafe methods of work4 ,no visionary schemes1 no ideal pictures4 ,just ,plain ,facts and ,practical ,suggestions are given4 ,every railroad employee who reads the book is a better and safer man to have in railroad service4 ,it gives just the information which will be the means of preventing many injuries and deaths4 ,all railroad employees should procure a copy1 read it1 and do their part in preventing accidents4 #afi pages4 ,pocket size4 ,fully illustrated4 ,price #ej cents ,train ,rule ,examinations ,made ,easy4 ,by ,g4 ,e4 ,,collingwood4 ,this is the only practical work on train rules in print4 ,every detail is covered1 and puzzling points are explained in simple1 comprehensive language1 making it a practical treatise for the ,train ,dispatcher1 ,engineman1 ,trainman1 and all others who have to do with the movements of trains4 ,contains complete and reliable information of the ,standard ,code of ,train ,rules for single track4 ,shows ,signals in ,colors1 as used on the different roads4 ,explains fully the practical application of train orders1 giving a clear and definite understanding of all orders which may be used4 ,the meaning and necessity for certain rules are explained in such a manner that the student may know beyond a doubt the rights conferred under any orders he may receive or the action required by certain rules4 ,as nearly all roads require trainmen to pass regular examinations1 a complete set of examination questions1 with their answers1 are included4 ,these will enable the student to pass the required examinations with credit to himself and the road for which he works4 #bnd ,edition1 ,revised4 #bef pages1 fully illustrated1 with ,train ,signals in ,colors4 ,price #a4be ,the ,walschaert and ,other ,modern ,radial ,valve ,gears for ,locomotives4 ,by ,,wm4 ,w4 ,,wood4 ,if you would thoroughly understand the ,walschaert ,valve ,gear you should possess a copy of this book1 as the author takes the plainest form of a steam engine--a stationary engine in the rough1 that will only turn its crank in one direction--and from it builds up1 with the reader's help1 a modern locomotive equipped with the ,walschaert ,valve ,gear1 complete4 ,the points discussed are clearly illustrated3 ,two large folding plates that show the positions of the valves of both inside or outside admission type1 as well as the links and other parts of the gear when the crank is at nine different points in its revolution1 are especially valuable in making the movement clear4 ,these employ sliding cardboard models which are contained in a pocket in the cover4 ,the book is divided into five general divisions1 as follows3 #a4 ,analysis of the gear4 #b4 ,designing and erecting the gear4 #c4 ,advantages of the gear4 #d4 ,questions and answers relating to the ,walschaert ,valve ,gear4 #e4 ,setting valves with the ,walschaert ,valve ,gear2 the three primary types of locomotive valve motion2 modern radial valve gears other than the ,walschaert2 the ,hobart ,all-free ,valve and ,valve ,gear1 with questions and answers on breakdowns2 the ,baker-,pilliod ,valve ,gear2 the ,improved ,baker-,pilliod ,valve ,gear1 with questions and answers on breakdowns4 ,the questions with full answers given will be especially valuable to firemen and engineers in preparing for an examination for promotion4 #bde pages4 #crd ,revised ,edition4 ,price #a4ej ,westinghouse ,e-,t ,air-,brake ,instruction ,pocket ,book4 ,by ,,wm4 ,w4 ,,wood1 ,air-,brake ,instructor4 ,here is a book for the railroad man1 and the man who aims to be one4 ,it is without doubt the only complete work published on the ,westinghouse ,e-,t ,locomotive ,brake ,equipment4 ,written by an ,air-,brake ,instructor who knows just what is needed4 ,it covers the subject thoroughly4 ,everything about the ,new ,westinghouse ,engine and ,tender ,brake ,equipment1 including the standard ,no4 #e and the ,perfected ,no4 #f style of brake1 is treated in detail4 ,written in plain ,english and profusely illustrated with ,colored ,plates1 which enable one to trace the flow of pressures throughout the entire equipment4 ,the best book ever published on the ,air ,brake4 ,equally good for the beginner and the advanced engineer4 ,will pass any one through any examination4 ,it informs and enlightens you on every point4 ,indispensable to every engineman and trainman4 ,contains examination questions and answers on the ,e-,t equipment4 ,covering what the ,e-,t ,brake is4 ,how it should be operated4 ,what to do when defective4 ,not a question can be asked of the engineman up for promotion1 on either the ,no4 #e or the ,no4 #f ,e-,t equipment1 that is not asked and answered in the book4 ,if you want to thoroughly understand the ,e-,t equipment get a copy of this book4 ,it covers every detail4 ,makes ,air-,brake troubles and examinations easy4 ,price #a4ej ,,machine-,,shop ,,practice ,american ,tool ,making and ,interchangeable ,manufacturing4 ,by ,j4 ,v4 ,,woodworth4 ,a shoppy book1 containing no theorizing1 no problematical or experimental devices4 ,there are no badly proportioned and impossible diagrams1 no catalogue cuts1 but a valuable collection of drawings and descriptions of devices1 the rich fruits of the author's own experience4 ,in its #ejj-odd pages the one subject only1 ,tool ,making1 and whatever relates thereto1 is dealt with4 ,the work stands without a rival4 ,it is a complete1 practical treatise1 on the art of ,american ,tool ,making and system of interchangeable manufacturing as carried on to-day in the ,united ,states4 ,in it are described and illustrated all of the different types and classes of small tools1 fixtures1 devices1 and special appliances which are in general use in all machine-manufacturing and metal-working establishments where economy1 capacity1 and interchangeability in the production of machined metal parts are imperative4 ,the science of jig making is exhaustively discussed1 and particular attention is paid to drill jigs1 boring1 profiling and milling fixtures and other devices in which the parts to be machined are located and fastened within the contrivances4 ,all of the tools1 fixtures1 and devices illustrated and described have been or are used for the actual production of work1 such as parts of drill presses1 lathes1 patented machinery1 typewriters1 electrical apparatus1 mechanical appliances1 brass goods1 composition parts1 mould products1 sheet-metal articles1 drop-forgings1 jewelry1 watches1 medals1 coins1 etc4 #eca pages4 ,price #d4jj ,,henley',s ,,encyclopedia ,,of ,,practical ,,engineering ,,and ,,allied ,,trades4 ,,edited by ,,joseph ,g4 ,,horner1 ,a4,m4,i41 ,m4,e4 ,this set of five volumes contains about #b1ejj pages with thousands of illustrations1 including diagrammatic and sectional drawings with full explanatory details4 ,this work covers the entire practice of ,civil and ,mechanical ,engineering4 ,the best known experts in all branches of engineering have contributed to these volumes4 ,the ,cyclopedia is admirably well adapted to the needs of the beginner and the self-taught practical man1 as well as the mechanical engineer1 designer1 draftsman1 shop superintendent1 foreman1 and machinist4 ,the work will be found a means of advancement to any progressive man4 ,it is encyclopedic in scope1 thorough and practical in its treatment on technical subjects1 simple and clear in its descriptive matter1 and without unnecessary technicalities or formulae4 ,the articles are as brief as may be and yet give a reasonably clear and explicit statement of the subject1 and are written by men who have had ample practical experience in the matters of which they write4 ,it tells you all you want to know about engineering and tells it so simply1 so clearly1 so concisely1 that one cannot help but understand4 ,as a work of reference it is without a peer4 ,complete set of five volumes1 price #be4jj ,the ,modern ,machinist4 ,by ,,john ,t4 ,,usher4 ,this is a book1 showing by plain description and by profuse engravings made expressly for the work1 all that is best1 most advanced1 and of the highest efficiency in modern machine-shop practice1 tools and implements1 showing the way by which and through which1 as ,mr4 ,maxim says ,american machinists have become and are the finest mechanics in the world4 ,indicating as it does1 in every line1 the familiarity of the author with every detail of daily experience in the shop1 it cannot fail to be of service to any man practically connected with the shaping or finishing of metals4 ,there is nothing experimental or visionary about the book1 all devices being in actual use and giving good results4 ,it might be called a compendium of shop methods1 showing a variety of special tools and appliances which will give new ideas to many mechanics1 from the superintendent down to the man at the bench4 ,it will be found a valuable addition to any machinist's library1 and should be consulted whenever a new or difficult job is to be done1 whether it is boring1 milling1 turning1 or planing1 as they are all treated m a practical manner4 ,fifth edition4 #cbj pages4 #bej illustrations4 ,price #b4ej ,,the ,,whole ,,field ,,of ,,mechanical ,,movements ,,covered ,,by ,,mr4 ,,hiscox',s ,,two ,,books ,we publish two books by ,gardner ,d4 ,hiscox that will keep you from inventing things that have been done before1 and suggest ways of doing things that you have not thought of before4 ,many a man spends time and money pondering over some mechanical problem1 only to learn1 after he has solved the problem1 that the same thing has been accomplished and put in practice by others long before4 ,time and money spent in an effort to accomplish what has already been accomplished are time and money ,,lost4 ,the whole field of mechanics1 every known mechanical movement1 and practically every device are covered by these two books4 ,if the thing you want has been invented1 it is illustrated in them4 ,if it hasn't been invented1 then you'll find in them the nearest things to what you want1 some movements or devices that will apply in your case1 perhaps2 or which will give you a key from which to work4 ,no book or set of books ever published is of more real value to the ,inventor1 ,draftsman1 or practical ,mechanic than the two volumes described below4 ,mechanical ,movements1 ,powers1 and ,devices4 ,by ,,gardner ,d4 ,,hiscox4 ,this is a collection of #a1hij engravings of different mechanical motions and appliances1 accompanied by appropriate text1 making it a book of great value to the inventor1 the draftsman1 and to all readers with mechanical tastes4 ,the book is divided into eighteen sections or chapters1 in which the subject-matter is classified under the following heads3 ,mechanical ,powers2 ,transmission of ,power2 ,measurement of ,power2 ,steam ,power2 ,air ,power ,appliances2 ,electric ,power and ,construction2 ,navigation and ,roads2 ,gearing2 ,motion and ,devices2 ,controlling ,motion2 ,horological2 ,mining2 ,mill and ,factory ,appliances2 ,construction and ,devices2 ,drafting ,devices2 ,miscellaneous ,devices1 etc4 #aeth ,edition4 #djj octavo pages4 ,price #c4jj ,mechanical ,appliances1 ,mechanical ,movements and ,novelties of ,construction4 ,by ,,gardner ,d4 ,,hiscox4 ,this is a supplementary volume to the one upon mechanical movements4 ,unlike the first volume1 which is more elementary in character1 this volume contains illustrations and descriptions of many combinations of motions and of mechanical devices and appliances found in different lines of machinery1 each device being shown by a line drawing with a description showing its working parts and the method of operation4 ,from the multitude of devices described and illustrated might be mentioned1 in passing1 such items as conveyors and elevators1 ,pony brakes1 thermometers1 various types of boilers1 solar engines1 oil-fuel burners1 condensers1 evaporators1 ,corliss and other valve gears1 governors1 gas engines1 water motors of various descriptions1 air ships1 motors and dynamos1 automobile and motor bicycles1 railway lock signals1 car couplers1 link and gear motions1 ball bearings1 breech-block mechanism for heavy guns1 and a large accumulation of others of equal importance4 ,one thousand specially made engravings4 #cif octavo pages4 ,fourth edition4 ,price #c4jj ,machine-,shop ,tools and ,shop ,practice4 ,by ,w4 ,h4 ,,vandervoort4 ,a work of #eee pages and #fgc illustrations1 describing in every detail the construction1 operation and manipulation of both hand and machine tools4 ,includes chapters on filing1 fitting and scraping surfaces2 on drills1 reamers1 taps and dies2 the lathe and its tools3 planers1 shapers1 and their tools2 milling machines and cutters2 gear cutters and gear cutting2 drilling machines and drill work2 grinding machines and their work2 hardening and tempering2 gearing1 belting and transmission machinery2 useful data and tables4 ,sixth edition4 ,price #c4jj ,machine-,shop ,arithmetic4 ,by ,,colvin-,,cheney4 ,this is an arithmetic of the things you have to do with daily4 ,it tells you plainly about3 how to find areas in figures2 how to find surface or volume of balls or spheres2 handy ways for calculating2 about compound gearing2 cutting screw threads on any lathe2 drilling for taps2 speeds of drills2 taps1 emery wheels1 grindstones1 milling cutters1 etc42 all about the ,metric system with conversion tables2 properties of metals2 strength of bolts and nuts2 decimal equivalent of an inch4 ,all sorts of machine-shop figuring and #a1jja other things1 any one of which ought to be worth more than the price of this book to you1 as it saves you the trouble of bothering the boss4 #fth ,edition4 #aca pages4 ,price #ej cents ,modern ,machine-,shop ,construction1 ,equipment and ,management4 ,by ,,oscar ,e4 ,,perrigo4 ,the only work published that describes the ,modern ,shop or ,manufacturing ,plant from the time the grass is growing on the site intended for it until the finished product is shipped4 ,just the book needed by those contemplating the erection of modern shop buildings1 the rebuilding and reorganization of old ones1 or the introduction of ,modern ,shop ,methods1 time and cost systems4 ,it is a book written and illustrated by a practical shop man for practical shop men who are too busy to read theories and want facts4 ,it is the most complete all-round book of its kind ever published4 ,second ,edition1 ,revised4 #chd large quarto pages4 #bai original and specially made illustrations4 #bnd ,revised and ,enlarged ,edition4 ,price #e4jj ,modern ,milling ,machines3 ,their ,design1 ,construction1 and ,operation4 ,by ,,joseph ,g4 ,,horner4 ,this book describes and illustrates the ,milling ,machine and its work in such a plain1 clear and forceful manner1 and illustrates the subject so clearly and completely1 that the up-to-date machinist1 student or mechanical engineer cannot afford to do without the valuable information which it contains4 ,it describes not only the early machines of this class1 but notes their gradual development into the splendid machines of the present day1 giving the design and construction of the various types1 forms1 and special features produced by prominent manufacturers1 ,american and foreign4 #cjd pages1 #cjj illustrations4 ,cloth4 ,price #d4jj ,shop ,kinks4 ,by ,,robert ,,grimshaw4 ,a book of #djj pages and #bbb illustrations1 being entirely different from any other book on machine-shop practice4 ,departing from conventional style1 the author avoids universal or common shop usage and limits his work to showing special ways of doing things better1 more cheaply and more rapidly than usual4 ,as a result the advanced methods of representative establishments of the world are placed at the disposal of the reader4 ,this book shows the proprietor where large savings are possible1 and how products may be improved4 ,to the employee it holds out suggestions that1 properly applied1 will hasten his advancement4 ,no shop can afford to be without it4 ,it bristles with valuable wrinkles and helpful suggestions4 ,it will benefit all1 from apprentice to proprietor4 ,every machinist1 at any age1 should study its pages4 ,fifth edition4 ,price #b4ej ,threads and ,thread ,cutting4 ,by ,,colvin and ,,stabel4 ,this clears up many of the mysteries of thread-cutting1 such as double and triple threads1 internal threads1 catching threads1 use of hobs1 etc4 ,contains a lot of useful hints and several tables4 ,third edition4 ,price #be cents ,,manual ,,training ,economics of ,manual ,training4 ,by ,,louis ,,rouillion4 ,the only book published that gives just the information needed by all interested in ,manual ,training1 regarding ,buildings1 ,equipment1 and ,supplies4 ,shows exactly what is needed for all grades of the work from the ,kindergarten to the ,high and ,normal ,school4 ,gives itemized lists of everything used in ,manual ,training ,work and tells just what it ought to cost4 ,also shows where to buy supplies1 etc4 ,contains #agd pages1 and is fully illustrated4 ,second edition4 ,price #a4ej ,,marine ,,engineering ,the ,naval ,architect's and ,shipbuilder's ,pocket ,book of ,formulae1 ,rules1 and ,tables and ,marine ,engineer's and ,surveyor's ,handy ,book of ,reference4 ,by ,,clement ,,mackrow and ,,lloyd ,,woollard4 ,the eleventh ,revised and ,enlarged ,edition of this most comprehensive work has just been issued4 ,it is absolutely indispensable to all engaged in the ,shipbuilding ,industry1 as it condenses into a compact form all data and formulae that are ordinarily required4 ,the book is completely up to date1 including among other subjects a section on ,aeronautics4 #gej pages1 limp leather binding4 ,price #e4jj net ,marine ,engines and ,boilers3 ,their ,design and ,construction4 ,by ,,dr4 ,g4 ,,bauer1 ,,leslie ,s4 ,,robertson and ,s4 ,,bryan ,,donkin4 ,in the words of ,dr4 ,bauer1 the present work owes its origin to an oft felt want of a condensed treatise embodying the theoretical and practical rules used in designing marine engines and boilers4 ,the need of such a work has been felt by most engineers engaged in the construction and working of marine engines1 not only by the younger men1 but also by those of greater experience4 ,the fact that the original ,german work was written by the chief engineer of the famous ,vulcan ,works1 ,stettin1 is in itself a guarantee that this book is in all respects thoroughly up-to-date1 and that it embodies all the information which is necessary for the design and construction of the highest types of marine engines and boilers4 ,it may be said that the motive power which ,dr4 ,bauer has placed in the fast ,german liners that have been turned out of late years from the ,stettin ,works represent the very best practice in marine engineering of the present day4 ,the work is clearly written1 thoroughly systematic1 theoretically sound2 while the character of the plans1 drawings1 tables1 and statistics is without reproach4 ,the illustrations are careful reproductions from actual working drawings1 with some well-executed photographic views of completed engines and boilers4 #gdd pages1 #eej illustrations and numerous tables4 ,cloth4 ,price #i4jj net ,,mining ,ore ,deposits1 with a ,chapter on ,hints to ,prospectors4 ,by ,j4 ,p4 ,,johnson4 ,this book gives a condensed account of the ore deposits at present known in ,south ,africa4 ,it is also intended as a guide to the prospector4 ,only an elementary knowledge of geology and some mining experience are necessary in order to understand this work4 ,with these qualifications1 it will materially assist one in his search for metalliferous mineral occurrences and1 so far as simple ores are concerned1 should enable one to form some idea of the possibilities of any he may find4 ,illustrated4 ,cloth4 ,price #b4jj ,practical ,coal ,mining4 ,by ,t4 ,h4 ,,cockin4 ,an important work1 containing #dbh pages and #bac illustrations1 complete with practical details1 which will intuitively impart to the reader not only a general knowledge of the principles of coal mining1 but also considerable insight into allied subjects4 ,the treatise is positively up-to-date in every instance1 and should be in the hands of every colliery engineer1 geologist1 mine operator1 superintendent1 foreman1 and all others who are interested in or connected with the industry4 #c;d ,edition4 ,cloth4 ,price #b4ej ,physics and ,chemistry of ,mining4 ,by ,t4 ,h4 ,,byrom4 ,a practical work for the use of all preparing for examinations in mining or qualifying for colliery managers' certificates4 ,the aim of the author in this excellent book is to place clearly before the reader useful and authoritative data which will render him valuable assistance in his studies4 ,the only work of its kind published4 ,the information incorporated in it will prove of the greatest practical utility to students1 mining engineers1 colliery managers1 and all others who are specially interested in the present-day treatment of mining problems4 #afj pages1 illustrated4 ,price #b4jj ,,pattern ,,making ,practical ,pattern ,making4 ,by ,f4 ,w4 ,,barrows4 ,this book1 now in its second edition1 is a comprehensive and entirely practical treatise on the subject of pattern making1 illustrating pattern work in both wood and metal1 and with definite instructions on the use of plaster of paris in the trade4 ,it gives specific and detailed descriptions of the materials used by pattern makers1 and describes the tools1 both those for the bench and the more interesting machine tools1 having complete chapters on the ,lathe1 the ,circular ,saw1 and the ,band ,saw4 ,it gives many examples of pattern work1 each one fully illustrated and explained with much detail4 ,these examples1 in their great variety1 offer much that will be found of interest to all pattern makers1 and especially to the younger ones1 who are seeking information on the more advanced branches of their trade4 ,in this second edition of the work will be found much that is new1 even to those who have long practised this exacting trade4 ,in the description of patterns as adapted to the ,moulding ,machine many difficulties which have long prevented the rapid and economical production of castings are overcome2 and this great1 new branch of the trade is given much space4 ,stripping plate and stool plate work and the less expensive vibrator1 or rapping plate work1 are all explained in detail4 ,plain1 every-day rules for lessening the cost of patterns1 with a complete system of cost keeping1 a detailed method of marking1 applicable to all branches of the trade1 with complete information showing what the pattern is1 its specific title1 its cost1 date of production1 material of which it is made1 the number of pieces and core-boxes1 and its location in the pattern safe1 all condensed into a most complete card record1 with cross index4 ,the book closes with an original and practical method for the inventory and valuation of patterns4 ,containing nearly #cej pages and #agj illustrations4 ,price #b4jj ,,perfumery ,perfumes and ,cosmetics3 ,their ,preparation and ,manufacture4 ,by ,g4 ,w4 ,,askinson1 ,perfumer4 ,a comprehensive treatise1 in which there has been nothing omitted that could be of value to the perfumer or manufacturer of toilet preparations4 ,complete directions for making handkerchief perfumes1 smelling-salts1 sachets1 fumigating pastilles2 preparations for the care of the skin1 the mouth1 the hair1 cosmetics1 hair dyes and other toilet articles are given1 also a detailed description of aromatic substances2 their nature1 tests of purity1 and wholesome manufacture1 including a chapter on synthetic products1 with formulas for their use4 ,a book of general as well as professional interest1 meeting the wants not only of the druggist and perfume manufacturer1 but also of the general public4 ,among the contents are3 #a4 ,the ,history of ,perfumery4 #b4 ,about ,aromatic ,substances in ,general4 #c4 ,odors from the ,vegetable ,kingdom4 #d4 ,the ,aromatic ,vegetable ,substances ,employed in ,perfumery4 #e4 ,the ,animal ,substances ,used in ,perfumery4 #f4 ,the ,chemical ,products ,used in ,perfumery4 #g4 ,the ,extraction of ,odors4 #h4 ,the ,special ,characteristics of ,aromatic ,substances4 #i ,the ,adulteration of ,essential ,oils and ,their ,recognition4 #aj4 ,synthetic ,products4 #aa4 ,table of ,physical ,properties of ,aromatic ,chemicals4 #ab4 ,the ,essences or ,extracts ,employed in ,perfumery4 #ac4 ,directions for ,making the ,most ,important ,essences and ,extracts4 #ad4 ,the ,division of ,perfumery4 #ae4 ,the ,manufacture of ,handkerchief ,perfumes4 #af4 ,formulas for ,handkerchief ,perfumes4 #ag4 ,ammoniacal and ,acid ,perfumes4 #ah4 ,dry ,perfumes4 #ai4 ,formulas for ,dry ,perfumes4 #bj4 ,the ,perfumes ,used for ,fumigation4 #ba4 ,antiseptic and ,therapeutic ,value of ,perfumes4 #bb4 ,classification of ,odors4 #bc4 ,some ,special ,perfumery ,products4 #bd4 ,hygiene and ,cosmetic ,perfumery4 #be4 ,preparations for the ,care of the ,skin4 #bf4 ,manufacture of ,casein4 #bg4 ,formulas for ,emulsions4 #bh4 ,formulas for ,cream4 #bi4 ,formulas for ,meals1 ,pastes and ,vegetable ,milk4 #cj4 ,preparations ,used for the ,hair4 #ca4 ,formulas for ,hair ,tonics and ,restorers4 #cb4 ,pomades and ,hair ,oils #cc4 ,formulas for the ,manufacture of ,pomades and ,hair ,oils4 #cd4 ,hair ,dyes and ,depilatories4 #ce4 ,wax ,pomades1 ,bandolines and ,brilliantines4 #cf4 ,skin ,cosmetics and ,face ,lotions4 #cg4 ,preparations for the ,nails4 #ch4 ,water ,softeners and ,bath ,salts4 #ci4 ,preparations for the ,care of the ,mouth4 #dj4 ,the ,colors ,used in ,perfumery4 #da4 ,the ,utensils ,used in the ,toilet4 ,fourth edition1 much enlarged and brought up to date4 ,nearly #djj pages1 illustrated4 ,price #e4jj ,,what ,,is ,,said ,,of ,,this ,,book3 ,the most satisfactory work on the subject of ,perfumery that we have ever seen4 ,we feel safe in saying that here is a book on ,perfumery that will not disappoint you1 for it has practical and excellent formulae that are within your ability to prepare readily4 ,we recommend the volume as worthy of confidence1 and say that no purchaser will be disappointed in securing from its pages good value for its cost1 and a large dividend on the same1 even if he should use but one per cent4 of its working formulae4 ,there is money in it for every user of its information4--,pharmaceutical ,record4 ,,plumbing ,mechanical ,drawing for ,plumbers4 ,by ,r4 ,m4 ,,starbuck4 ,a concise1 comprehensive and practical treatise on the subject of mechanical drawing in its various modern applications to the work of all who are in any way connected with the plumbing trade4 ,nothing will so help the plumber in estimating and in explaining work to customers and workmen as a knowledge of drawing1 and to the workman it is of inestimable value if he is to rise above his position to positions of greater responsibility4 ,among the chapters contained are3 #a4 ,value to plumber of knowledge of drawing2 tools required and their use2 common views needed in mechanical drawing4 #b4 ,perspective versus mechanical drawing in showing plumbing construction4 #c4 ,correct and incorrect methods in plumbing drawing2 plan and elevation explained4 #d4 ,floor and cellar plans and elevation2 scale drawings2 use of triangles4 #e4 ,use of triangles2 drawing of fittings1 traps1 etc4 #f4 ,drawing plumbing elevations and fittings4 #g4 ,instructions in drawing plumbing elevations4 #h4 ,the drawing of plumbing fixtures2 scale drawings4 #i4 ,drawings of fixtures and fittings4 #aj4 ,inking of drawings4 #aa4 ,shading of drawings4 #ab4 ,shading of drawings4 #ac4 ,sectional drawings2 drawing of threads4 #ad4 ,plumbing elevations from architect's plan4 #ae4 ,elevations of separate parts of the plumbing system4 #af4 ,elevations from the architect's plans4 #ag4 ,drawings of detail plumbing connections4 #ah4 ,architect's plans and plumbing elevations of residence4 #ai4 ,plumbing elevations of residence 7continued72 plumbing plans for cottage4 #bj4 ,plumbing elevations2 roof connections4 #ba4 ,plans and plumbing elevations for six-flat building4 #bb4 ,drawing of various parts of the plumbing system2 use of scales4 #bc4 ,use of architect's scales4 #bd4 ,special features in the illustrations of country plumbing4 #be4 ,drawing of wrought-iron piping1 valves1 radiators1 coils1 etc4 #bf4 ,drawing of piping to illustrate heating systems4 #aej illustrations4 ,price #a4ej ,modern ,plumbing ,illustrated4 ,by ,r4 ,m4 ,,starbuck4 ,this book represents the highest standard of plumbing work4 ,it has been adopted and used as a reference book by the ,united ,states ,government in its sanitary work in ,cuba1 ,porto ,rico and the ,philippines1 and by the principal ,boards of ,health of the ,united ,states and ,canada4 ,it gives connections1 sizes and working data for all fixtures and groups of fixtures4 ,it is helpful to the master plumber in demonstrating to his customers and in figuring work4 ,it gives the mechanic and student quick and easy access to the best modern plumbing practice4 ,suggestions for estimating plumbing construction are contained in its pages4 ,this book represents1 in a word1 the latest and best up-to-date practice and should be in the hands of every architect1 sanitary engineer and plumber who wishes to keep himself up to the minute on this important feature of construction4 ,contains following chapters1 each illustrated with a full-page plate3 ,kitchen sink1 laundry tubs1 vegetable wash sink2 lavatories1 pantry sinks1 contents of marble slabs2 bath tub1 foot and sitz bath1 shower bath2 water closets1 venting of water closets2 low-down water closets1 water closets operated by flush valves1 water closet range2 slop sink1 urinals1 the bidet2 hotel and restaurant sink1 grease trap2 refrigerators1 safe wastes1 laundry waste1 lines of refrigerators1 bar sinks1 soda fountain sinks2 horse stall1 frost-proof water closets2 connections for ,s traps1 venting2 connections for drum traps2 soil-pipe connections2 supporting of soil pipe2 main trap and fresh-air inlet3 floor drains and cellar drains1 subsoil drainage2 water closets and floor connections2 local venting2 connections for bath rooms2 connections for bath rooms1 continued2 examples of poor practice2 roughing work ready for test2 testing of plumbing systems2 method of continuous venting2 continuous venting for two-floor work2 continuous venting for two lines of fixtures on three or more floors2 continuous venting of water closets2 plumbing for cottage house2 construction for cellar piping2 plumbing for residence1 use of special fittings2 plumbing for two-flat house3 plumbing for apartment building1 plumbing for double apartment building2 plumbing for office building2 plumbing for public toilet rooms2 plumbing for public toilet rooms1 continued2 plumbing for bath establishment2 plumbing for engine house1 factory plumbing1 automatic flushing for schools1 factories1 etc42 use of flushing valves2 urinals for public toilet rooms2 the ,durham system1 the destruction of pipes by electrolysis2 construction of work without use of lead2 automatic sewage lift2 automatic sump tank2 country plumbing2 construction of cesspools2 septic tank and automatic sewage siphon2 water supply for country house2 thawing of water mains and service by electricity2 double boilers2 hot water supply of large buildings2 automatic control of hot-water tank2 suggestions for estimating plumbing construction4 #djg octavo pages1 fully illustrated by #eg full-page engravings4 ,third1 revised and enlarged edition1 just issued4 ,price #d4jj ,standard ,practical ,plumbing4 ,by ,r4 ,m4 ,,starbuck4 ,a complete practical treatise of #dej pages1 covering the subject of ,modern ,plumbing in all its branches1 a large amount of space being devoted to a very complete and practical treatment of the subject of ,hot ,water ,supply and ,circulation and ,range ,boiler ,work4 ,its thirty chapters include about every phase of the subject one can think of1 making it an indispensable work to the master plumber1 the journeyman plumber1 and the apprentice plumber1 containing chapters on3 the plumber's tools2 wiping solder2 composition and use2 joint wiping2 lead work2 traps2 siphonage of traps2 venting2 continuous venting2 house sewer and sewer connections2 house drain2 soil piping1 roughing2 main trap and fresh air inlet2 floor1 yard1 cellar drains1 rain leaders1 etc42 fixture wastes2 water closets2 ventilation2 improved plumbing connections2 residence plumbing2 plumbing for hotels1 schools1 factories1 stables1 etc42 modern country plumbing2 filtration of sewage and water supply2 hot and cold supply2 range boilers2 circulation2 circulating pipes2 range boiler problems2 hot water for large buildings2 water lift and its use2 multiple connections for hot water boilers2 heating of radiation by supply system2 theory for the plumber2 drawing for the plumber4 ,fully illustrated by #cdg engravings4 ,price #c4jj ,,recipe ,,book ,henley's ,twentieth ,century ,book of ,recipes1 ,formulas and ,processes4 ,edited by ,,gardner ,d4 ,,hiscox4 ,the most valuable ,techno-chemical ,formula ,book published1 including over #aj1jjj selected scientific1 chemical1 technological1 and practical recipes and processes4 ,this is the most complete ,book of ,formulas ever published1 giving thousands of recipes for the manufacture of valuable articles for everyday use4 ,hints1 ,helps1 ,practical ,ideas1 and ,secret ,processes are revealed within its pages4 ,it covers every branch of the useful arts and tells thousands of ways of making money1 and is just the book everyone should have at his command4 ,modern in its treatment of every subject that properly falls within its scope1 the book may truthfully be said to present the very latest formulas to be found in the arts and industries1 and to retain those processes which long experience has proven worthy of a permanent record4 ,to present here even a limited number of the subjects which find a place in this valuable work would be difficult4 ,suffice to say that in its pages will be found matter of intense interest and immeasurably practical value to the scientific amateur and to him who wishes to obtain a knowledge of the many processes used in the arts1 trades and manufacture1 a knowledge which will render his pursuits more instructive and remunerative4 ,serving as a reference book to the small and large manufacturer and supplying intelligent seekers with the information necessary to conduct a process1 the work will be found of inestimable worth to the ,metallurgist1 the ,photographer1 the ,perfumer1 the ,painter1 the ,manufacturer of ,glues1 ,pastes1 ,cements1 and ,mucilages1 the ,compounder of ,alloys1 the ,cook1 the ,physician1 the ,druggist1 the ,electrician1 the ,brewer1 the ,engineer1 the ,foundryman1 the ,machinist1 the ,potter1 the ,tanner1 the ,confectioner1 the ,chiropodist1 the ,manicurist1 the ,manufacturer of ,chemical ,novelties and ,toilet ,preparations1 the ,dyer1 the ,electroplater1 the ,enameler1 the ,hat ,maker1 the ,ink ,manufacturer1 the ,optician1 the ,farmer1 the ,dairyman1 the ,paper ,maker1 the ,wood and ,metal ,worker1 the ,chandler and ,soap ,maker1 the ,veterinary ,surgeon1 and the ,technologist in general4 ,a mine of information1 and up-to-date in every respect4 ,a book which will prove of value to ,,everyone1 as it covers every branch of the ,useful ,arts4 ,every home needs this book2 every office1 every factory1 every store1 every public and private enterprise--,,everywhere--should have a copy4 #hjj pages4 ,price #c4jj ,,what ,,is ,,said ,,of ,,this ,,book3 ,your ,twentieth ,century ,book of ,recipes1 ,formulas1 and ,processes duly received4 ,i am glad to have a copy of it1 and if ,i could not replace it1 money couldn't buy it4 ,it is the best thing of the sort ,i ever saw4 7,signed7 ,m4 ,e4 ,,trux1 ,sparta1 ,wis4 ,there are few persons who would not be able to find in the book some single formula that would repay several times the cost of the book4--,merchants' ,record and ,show ,window4 ,i purchased your book1 ',henley's ,twentieth ,century ,book of ,recipes1 ,formulas and ,processes1' about a year ago and it is worth its weight in gold4--,,wm4 ,h4 ,,murray1 ,bennington1 ,vt4 ,,one ,,of ,,the ,,world',s ,,most ,,useful ,,books ,some time ago ,i got one of your ',twentieth ,century ,books of ,formulas1' and have made my living from it ever since4 ,i am alone since my husband's death with two small children to care for and am trying so hard to support them4 ,i have customers who take from me ,toilet ,articles ,i put up1 following directions given in the book1 and ,i have found everyone of them to be fine4--,,mrs4 ,j4 ,h4 ,,mcmaken1 ,west ,toledo1 ,ohio4 ,,rubber ,rubber ,hand ,stamps and the ,manipulation of ,india ,rubber4 ,,by ,t4 ,o',,conor ,,sloane4 ,this book gives full details on all points1 treating in a concise and simple manner the elements of nearly everything it is necessary to understand for a commencement in any branch of the ,india ,rubber ,manufacture4 ,the making of all kinds of ,rubber ,hand ,stamps1 ,small ,articles of ,india ,rubber1 ,u4 ,s4 ,government ,composition1 ,dating ,hand ,stamps1 the ,manipulation of ,sheet ,rubber1 ,toy ,balloons1 ,india ,rubber ,solutions1 ,cements1 ,blackings1 ,renovating1 ,varnish1 and ,treatment for ,india ,rubber ,shoes1 etc42 the ,hektograph ,stamp ,inks1 and ,miscellaneous ,notes1 with a ,short ,account of the ,discovery1 ,collection and ,manufacture of ,india ,rubber1 are set forth in a manner designed to be readily understood1 the explanations being plain and simple4 ,including a chapter on ,rubber ,tire ,making and ,vulcanizing2 also a chapter on the uses of rubber in ,surgery and ,dentistry4 #crd ,revised and ,enlarged ,edition4 #age pages4 ,illustrated #a4jj ,,saws ,saw ,filing and ,management of ,saws4 ,by ,,robert ,,grimshaw4 ,a practical hand-book on filing1 gumming1 swaging1 hammering1 and the brazing of band saws1 the speed1 work1 and power to run circular saws1 etc4 ,a handy book for those who have charge of saws1 or for those mechanics who do their own filing1 as it deals with the proper shape and pitches of saw teeth of all kinds and gives many useful hints and rules for gumming1 setting1 and filing1 and is a practical aid to those who use saws for any purpose4 ,complete tables of proper shape1 pitch1 and saw teeth as well as sizes and number of teeth of various saws are included4 #crd ,edition1 ,revised and ,enlarged4 ,illustrated4 ,price #a4jj ,,steam ,,engineering ,american ,stationary ,engineering4 ,by ,w4 ,e4 ,,crane4 ,this book begins at the boiler room and takes in the whole power plant4 ,a plain talk on every-day work about engines1 boilers1 and their accessories4 ,it is not intended to be scientific or mathematical4 ,all formulas are in simple form so that any one understanding plain arithmetic can readily understand any of them4 ,the author has made this the most practical book in print2 has given the results of his years of experience1 and has included about all that has to do with an engine room or a power plant4 ,you are not left to guess at a single point4 ,you are shown clearly what to expect under the various conditions2 how to secure the best results2 ways of preventing shut downs and repairs2 in short1 all that goes to make up the requirements of a good engineer1 capable of taking charge of a plant4 ,it's plain enough for practical men and yet of value to those high in the profession4 ,a partial list of contents is3 ,the boiler room1 cleaning boilers1 firing1 feeding2 pumps1 inspection and repair2 chimneys1 sizes and cost2 piping2 mason work2 foundations2 testing cement2 pile driving2 engines1 slow and high speed2 valves2 valve setting2 ,corliss engines1 setting valves1 single and double eccentric2 air pumps and condensers2 different types of condensers2 water needed2 lining up2 pounds2 pins not square in crosshead or crank2 engineers' tools2 pistons and piston rings2 bearing metal2 hardened copper2 drip pipes from cylinder jacket2 belts1 how made1 care of2 oils2 greases2 testing lubricants2 rules and tables1 including steam tables2 areas of segments2 squares and square roots2 cubes and cube root2 areas and circumferences of circles4 ,notes on3 ,brick work2 explosions2 pumps2 pump valves2 heaters1 economizers2 safety valves2 lap1 lead1 and clearance4 ,has a complete examination for a license1 etc41 etc4 #crd ,edition4 #cde pages1 illustrated4 ,price #b4jj ,engine ,runner's ,catechism4 ,by ,,robert ,,grimshaw4 ,a practical treatise for the stationary engineer1 telling how to erect1 adjust1 and run the principal steam engines in use in the ,united ,states4 ,describing the principal features of various special and well-known makes of engines3 ,temper ,cut-off1 ,shipping and ,receiving ,foundations1 ,erecting and ,starting1 ,valve ,setting1 ,care and ,use1 ,emergencies1 ,erecting and ,adjusting ,special ,engines4 ,the questions asked throughout the catechism are plain and to the point1 and the answers are given in such simple language as to be readily understood by anyone4 ,all the instructions given are complete and up-to-date2 and they are written in a popular style1 without any technicalities or mathematical formulae4 ,the work is of a handy size for the pocket1 clearly and well printed1 nicely bound1 and profusely illustrated4 ,to young engineers this catechism will be of great value1 especially to those who may be preparing to go forward to be examined for certificates of competency2 and to engineers generally it will be of no little service1 as they will find in this volume more really practical and useful information than is to be found anywhere else within a like compass4 #chg pages4 #gth ,edition4 ,price #b4jj ,modern ,steam ,engineering in ,theory and ,practice4 ,by ,,gardner ,d4 ,,hiscox4 ,this is a complete and practical work issued for ,stationary ,engineers and ,firemen1 dealing with the care and management of boilers1 engines1 pumps1 superheated steam1 refrigerating machinery1 dynamos1 motors1 elevators1 air compressors1 and all other branches with which the modern engineer must be familiar4 ,nearly #bjj questions with their answers on steam and electrical engineering1 likely to be asked by the ,examining ,board1 are included4 ,among the chapters are3 ,historical3 steam and its properties2 appliances for the generation of steam2 types of boilers2 chimney and its work2 heat economy of the feed water2 steam pumps and their work2 incrustation and its work2 steam above atmospheric pressure2 flow of steam from nozzles2 superheated steam and its work2 adiabatic expansion of steam2 indicator and its work2 steam engine proportions2 slide valve engines and valve motion2 ,corliss engine and its valve gear2 compound engine and its theory2 triple and multiple expansion engine2 steam turbine2 refrigeration2 elevators and their management2 cost of power2 steam engine troubles2 electric power and electric plants4 #dhg pages1 #dje engravings4 #crd ,edition4 ,price #c4jj ,steam ,engine ,catechism4 ,by ,,robert ,,grimshaw4 ,this unique volume of #dac pages is not only a catechism on the question and answer principle but it contains formulas and worked-out answers for all the ,steam problems that appertain to operation and management of the ,steam ,engine4 ,illustrations of various valves and valve gear with their principles of operation are given4 ,thirty-four ,tables that are indispensable to every engineer and fireman that wishes to be progressive and is ambitious to become master of his calling are within its pages4 ,it is a most valuable instructor in the service of ,steam ,engineering4 ,leading engineers have recommended it as a valuable educator for the beginner as well as a reference book for the engineer4 ,it is thoroughly indexed for every detail4 ,every essential question on the ,steam ,engine with its answer is contained in this valuable work4 #afth ,edition4 ,price #b4jj ,steam ,engineer's ,arithmetic4 ,by ,,colvin-,,cheney4 ,a practical pocket-book for the steam engineer4 ,shows how to work the problems of the engine room and shows why4 ,tells how to figure horsepower of engines and boilers2 area of boilers2 has tables of areas and circumferences2 steam tables2 has a dictionary of engineering terms4 ,puts you on to all of the little kinks in figuring whatever there is to figure around a power plant4 ,tells you about the heat unit2 absolute zero2 adiabatic expansion2 duty of engines2 factor of safety2 and a thousand and one other things2 and everything is plain and simple--not the hardest way to figure1 but the easiest4 #bnd ,edition4 ,price #ej ,cents ,engine ,tests and ,boiler ,efficiencies4 ,by ,j4 ,,buchetti4 ,this work fully describes and illustrates the method of testing the power of steam engines1 turbines and explosive motors4 ,the properties of steam and the evaporative power of fuels4 ,combustion of fuel and chimney draft2 with formulas explained or practically computed4 #bee pages1 #agi illustrations4 ,price #c4jj ,horsepower ,chart4 ,shows the horsepower of any stationary engine without calculation4 ,no matter what the cylinder diameter of stroke1 the steam pressure of cut-off1 the revolutions1 or whether condensing or non-condensing1 it's all there4 ,easy to use4 accurate1 and saves time and calculations4 ,especially useful to engineers and designers4 ,price #ej ,cents ,,steam ,,heating ,,and ,,ventilation ,practical ,steam1 ,hot-,water ,heating and ,ventilation4 ,by ,a4 ,g4 ,,king4 ,this book is the standard and latest work published on the subject and has been prepared for the use of all engaged in the business of steam1 hot-water heating1 and ventilation4 ,it is an original and exhaustive work4 ,tells how to get heating contracts1 how to install heating and ventilating apparatus1 the best business methods to be used1 with ,tricks of the ,trade for shop use4 ,rules and data for estimating radiation and cost and such tables and information as make it an indispensable work for everyone interested in steam1 hot-water heating1 and ventilation4 ,it describes all the principal systems of steam1 hot-water1 vacuum1 vapor1 and vacuum-vapor heating1 together with the new accelerated systems of hot-water circulation1 including chapters on up-to-date methods of ventilation and the fan or blower system of heating and ventilation4 ,containing chapters on3 ,i4 ,introduction4 ,,ii4 ,heat4 ,,iii4 ,evolution of artificial heating apparatus4 ,,iv4 ,boiler surface and settings4 ,v4 ,the chimney flue4 ,,vi4 ,pipe and fittings4 ,,vii4 ,valves1 various kinds4 ,,viii4 ,forms of radiating surfaces4 ,,ix4 ,locating of radiating surfaces4 ,x4 ,estimating radiation4 ,,xi4 ,steam-heating apparatus ,,xii4 ,exhaust-steam heating4 ,,xiii4 ,hot-water heating4 ,,xiv4 ,pressure systems of hot-water work4 ,,xv4 ,hot-water appliances4 ,,xvi4 ,greenhouse heating4 ,,xvii4 ,vacuum vapor and vacuum exhaust heating4 ,,xviii4 ,miscellaneous heating4 ,,xix4 ,radiator and pipe connections4 ,,xx4 ,ventilation4 ,,xxi4 ,mechanical ventilation and hot-blast heating4 ,,xxii4 ,steam appliances4 ,,xxiii4 ,district heating4 ,,xxiv4 ,pipe and boiler covering4 ,,xxv4 ,temperature regulation and heat control4 ,,xxvi4 ,business methods4 ,,xxvii4 ,miscellaneous4 ,,xxviii4 ,rules1 tables1 and useful information4 #cfg pages1 #cjj detailed engravings4 #bnd ,edition--,revised4 ,price #c4jj ,five ,hundred ,plain ,answers to ,direct ,questions on ,steam1 ,hot-,water1 ,vapor and ,vacuum ,heating ,practice4 ,by ,,alfred ,g4 ,,king4 ,this work1 just off the press1 is arranged in question and answer form2 it is intended as a guide and text-book for the younger1 inexperienced fitter and as a reference book for all fitters4 ,this book tells how and also tells why4 ,no work of its kind has ever been published4 ,it answers all the questions regarding each method or system that would be asked by the steam fitter or heating contractor1 and may be used as a text or reference book1 and for examination questions by ,trade ,schools or ,steam ,fitters' ,associations4 ,rules1 data1 tables and descriptive methods are given1 together with much other detailed information of daily practical use to those engaged in or interested in the various methods of heating4 ,valuable to those preparing for examinations4 ,answers every question asked relating to modern ,steam1 ,hot-,water1 ,vapor and ,vacuum ,heating4 ,among the contents are3 ,the ,theory and ,laws of ,heat4 ,methods of ,heating4 ,chimneys and ,flues4 ,boilers for ,heating4 ,boiler ,trimmings and ,settings4 ,radiation4 ,steam ,heating4 ,boiler1 ,radiator and ,pipe ,connections for ,steam ,heating4 ,hot ,water ,heating4 ,the ,two-,pipe ,gravity ,system of ,hot ,water ,heating4 ,the ,circuit ,system of ,hot ,water ,heating4 ,the ,overhead ,system of ,hot ,water ,heating4 ,boiler1 ,radiator and ,pipe ,connections for ,gravity ,systems of ,hot ,water ,heating4 ,accelerated ,hot ,water ,heating4 ,expansion ,tank ,connections4 ,domestic ,hot ,water ,heating4 ,valves and ,air ,valves4 ,vacuum ,vapor and ,vacuo-,vapor ,heating4 ,mechanical ,systems of ,vacuum ,heating4 ,non-,mechanical ,vacuum ,systems4 ,vapor ,systems4 ,atmospheric and ,modulating ,systems4 ,heating ,greenhouses4 ,information1 ,rules and ,tables4 #bjj pages1 #abg illustrations4 ,octavo4 ,cloth4 ,price #a4ej ,,steel ,steel3 ,its ,selection1 ,annealing1 ,hardening1 and ,tempering4 ,by ,e4 ,r4 ,,markham4 ,this work was formerly known as ,the ,american ,steel ,worker1 but on the publication of the new1 revised edition1 the publishers deemed it advisable to change its title to a more suitable one4 ,it is the standard work on ,hardening1 ,tempering1 and ,annealing ,steel of all kinds4 ,this book tells how to select1 and how to work1 temper1 harden1 and anneal steel for everything on earth4 ,it doesn't tell how to temper one class of tools and then leave the treatment of another kind of tool to your imagination and judgment1 but it gives careful instructions for every detail of every tool1 whether it be a tap1 a reamer or just a screw-driver4 ,it tells about the tempering of small watch springs1 the hardening of cutlery1 and the annealing of dies4 ,in fact1 there isn't a thing that a steel worker would want to know that isn't included4 ,it is the standard book on selecting1 hardening and tempering all grades of steel4 ,among the chapter headings might be mentioned the following subjects3 ,introduction2 the workman2 steel2 methods of heating2 heating tool steel2 forging2 annealing2 hardening baths2 baths for hardening2 hardening steel2 drawing the temper after hardening2 examples of hardening2 pack hardening2 case hardening2 spring tempering2 making tools of machine steel2 special steels2 steel for various tools2 causes of trouble2 high-speed steels1 etc4 #djj pages4 ,very fully illustrated4 ,fourth edition4 ,price #b4ej ,hardening1 ,tempering1 ,annealing1 and ,forging of ,steel4 ,by ,j4 ,v4 ,,woodworth4 ,a new work treating in a clear1 concise manner all modern processes for the heating1 annealing1 forging1 welding1 hardening and tempering of steel1 making it a book of great practical value to the metal-working mechanic in general1 with special directions for the successful hardening and tempering of all steel tools used in the arts1 including milling cutters1 taps1 thread dies1 reamers1 both solid and shell1 hollow mills1 punches and dies1 and all kinds of sheet-metal working tools1 shear blades1 saws1 fine cutlery1 and metal-cutting tools of all description1 as well as for all implements of steel both large and small4 ,in this work the simplest and most satisfactory hardening and tempering processes are given4 ,the uses to which the leading brands of steel may be adapted are concisely presented1 and their treatment for working under different conditions explained1 also the special methods for the hardening and tempering of special brands4 ,a chapter devoted to the different processes for case-hardening is also included1 and special reference made to the adaptation of machinery steel for tools of various kinds1 ,fourth edition4 #bhh pages4 #bja illustrations4 ,price #b4ej ,,tractors ,the ,modern ,gas ,tractor4 ,by ,,victor ,w4 ,,page1 ,m4,e4 ,a complete treatise describing all types and sizes of gasoline1 kerosene and oil tractors4 ,considers design and construction exhaustively1 gives complete instructions for care1 operation and repair1 outlines all practical applications on the road and in the field4 ,the best and latest work on farm tractors and tractor power plants4 ,a work needed by farmers1 students1 blacksmiths1 mechanics1 salesmen1 implement dealers1 designers1 and engineers4 ,second edition1 revised and enlarged4 #ejd pages4 ,nearly #cjj illustrations and folding plates4 ,price #b4jj ,,turbines ,marine ,steam ,turbines4 ,by ,,dr4 ,g4 ,,bauer and ,o4 ,,lasche4 ,assisted by ,e4 ,,ludwig and ,h4 ,,vogel4 ,translated from the ,german and edited by ,m4 ,g4 ,s4 ,swallow4 ,the book is essentially practical and discusses turbines in which the full expansion of steam passes through a number of separate turbines arranged for driving two or more shafts1 as in the ,parsons system1 and turbines in which the complete expansion of steam from inlet to exhaust pressure occurs in a turbine on one shaft1 as in the case of the ,curtis machines4 ,it will enable a designer to carry out all the ordinary calculation necessary for the construction of steam turbines1 hence it fills a want which is hardly met by larger and more theoretical works4 ,numerous tables1 curves and diagrams will be found1 which explain with remarkable lucidity the reason why turbine blades are designed as they are1 the course which steam takes through turbines of various types1 the thermodynamics of steam turbine calculation1 the influence of vacuum on steam consumption of steam turbines1 etc4 ,in a word1 the very information which a designer and builder of steam turbines most requires4 ,large octavo1 #bad pages4 ,fully illustrated and containing eighteen tables1 including an entropy chart4 ,price1 net #c4ej ,,watch ,,making ,watchmaker's ,handbook4 ,by ,,claudius ,,saunier4 ,no work issued can compare with this book for clearness and completeness4 ,it contains #dih pages and is intended as a workshop companion for those engaged in watch-making and allied mechanical arts4 ,nearly #bej engravings and fourteen plates are included4 ,this is the standard work on watch-making4 ,price #c4jj ,,welding ,automobile ,welding with the ,oxy-,acetylene ,flame4 ,by ,m4 ,,keith ,,dunham4 ,explains in a simple manner apparatus to be used1 its care1 and how to construct necessary shop equipment4 ,proceeds then to the actual welding of all automobile parts1 in a manner understandable by every one4 ,gives principles never to be forgotten4 ,aluminum1 cast iron1 steel1 copper1 brass1 bronze1 and malleable iron are fully treated1 as well as a clear explanation of the proper manner to burn the carbon out of the combustion head4 ,this book is of utmost value1 since the perplexing problems arising when metal is heated to a melting point are fully explained and the proper methods to overcome them shown4 #afg pages1 fully illustrated4 ,price #a4jj ,every ,practical ,man ,needs ,a ,magazine ,which ,will ,tell ,him ,how ,to ,make ,and ,do ,things ,have us enter your subscription to the best mechanical magazine on the market4 ,only one dollar a year for twelve numbers4 ,subscribe today to ,everyday ,engineering ,a monthly magazine devoted to practical mechanics for everyday men4 ,its aim is to popularize engineering as a science1 teaching the elements of applied mechanics and electricity in a straightforward and understandable manner4 ,the magazine maintains its own experimental laboratory where the devices described in articles submitted to the ,editor are first tried out and tested before they are published4 ,this important innovation places the standard of the published material very high1 and it insures accuracy and dependability4 ,the magazine is the only one in this country that specializes in practical model building4 ,articles in past issues have given comprehensive designs for many model boats1 including submarines and chasers1 model steam and gasoline engines1 electric motors and generators1 etc41 etc4 ,this feature is a permanent one in this magazine4 ,another popular department is that devoted to automobiles and airplanes4 ,care1 maintenance1 and operation receive full and authoritative treatment4 ,every article is written from the practical1 everyday man1 standpoint rather than from that of the professional4 ,the magazine entertains while it instructs4 ,it is a journal of practical1 dependable information given in such a style that it may be readily assimilated and applied by the man with little or no technical training4 ,the aim is to place before the man who leans toward practical mechanics1 a series of concise1 crisp1 readable talks on what is going on and how it is done4 ,these articles are profusely illustrated with clear1 snappy photographs1 specially posed to illustrate the subject in the magazine's own studio by its own staff of technically-trained illustrators and editors4 ,the subscription price of the magazine is one dollar per year of twelve numbers4 ,sample copy sent on receipt of ten cents4 ,enter your subscription to this practical magazine with your bookseller4 ,the ,norman ,w4 ,henley ,publishing ,co41 #b ,west #deth ,street1 ,new ,york ---------------------------------------- ------------------------- ,,transcriber',s ,,notes ,general remarks3 ,there are some differences in wording between the ,table of ,contents1 the lists of sections per chapter1 and the actual section titles4 ,their meaning is clear1 and they have been left as they were in the original work4 ,page #ef1 table3 ,fig4 #h in the first column does not refer to ,fig4 #h in this work4 ,the original work does not have a ,figure #hi4 ,page #cjc1 table3 it is uncertain what free with kerosene means1 there may be a word omitted4 ,page #edd1 entirely censored4 ,it is not clear what this page originally contained 7possibly a table71 since text and numbering of illustrations are uninterrupted4 ,the text ,,censored has been moved to after the first paragraph of the section on ,mercedes ,engines4 ,the ,list of ,illustrations does not occur in the original work4 ,changes made3 ,the text of the original work 7including inconsistencies in accents1 spelling1 hyphenation and lay-out1 and differences between the main text1 illustrations and advertisements7 has been followed1 except when listed below4 ,only some minor obvious typographical errors have been corrected silently4 ,where the author used x for multiplication1 this has been replaced by x in the body of the text 7not in the advertisements or illustrations74 ,the illustrations have been moved so as not to disrupt the flow of the text4 ,engine and aircraft types are not always named consistently in the original2 ,curtiss engine ,o ,x #b1 ,,ox-#b and #j,x#b have all been changed to ,,ox-#b1 ,curtiss aircraft ,,jn#d and ,,jn-#d to ,,jn-#d4 ,multi-page tables3 repeated headings have been removed1 and the tables treated as one consecutive table4 ,page #bb3 ,the product of has been moved into the first formula4 ,page #be3 ,when ,b x r ,m changed to ,when ,p x r ,m4 ,page #gd3 4#bbe _/ #gge 4#bije changed to 4#bbe _/ 4#gge 4#bije4 ,page #acg 7caption73 ,bavary changed to ,baverey as elsewhere4 ,page #agb3 evidently changed to evident4 ,page #bad3 drop to ,o changed to drop to #j4 ,page #bdh3 actual from a common changed to actuated from a common4 ,page #bef3 values changed to valves4 ,page #bhj3 ,fig4 #f changed to ,fig4 #aab4 ,page #cjf3 ,fig4 #abg1 ,b changed to ,fig4 #abg1 ,c 7#bnd reference74 ,page #cbd3 ,rhone changed to ,le ,rhone as elsewhere4 ,page #ccd3 ,check values changed to ,check valves4 ,page #cfd3 ,le,rhone changed to ,le ,rhone as elsewhere4 ,page #cij3 ,fig4 #fb1 ,d changed to ,fig4 #afh1 ,b4 ,page #djh3 ,stilson changed to ,stillson as elsewhere4 ,page #dij3 both valves changed to both halves4 ,page #ead3 standard ratio is #e4c changed to standard ratio is #e3c4 ,page #ebi3 gallons per minute #a1djj ,r4 ,p4 ,m4 changed to gallons per minute at #a1djj ,r4 ,p4 ,m4 ,page #edf3 ,hispano ,suiza changed to ,hispano-,suiza as elsewhere4 ,page #eef3 ,diameter of crank-shaft1 #ef mm4 changed to ,diameter of crank-shaft1 #ee mm4 ,page #g 7advertisements73 ,hazlehurst ,field changed to ,hazelhurst ,field4 ,page #ba 7advertisements73 ,rhose ,island ,compound changed to ,rhode ,island ,compound4 ,index3 ,shebler changed to ,schebler1 camshaft to cam-shaft1 wristpin to wrist-pin1 etc4 7all as in text74 ---------------------------------------- -------------------------